Getting back to DMA mode in Windows XP

CD-ROM and DVD-ROM dri­ves can revert to using PIO mode, despite being set to use "DMA if Avail­able." Here's how to make Win­dows XP rede­tect the DMA capa­bil­i­ties of the drives.

CD-ROM and DVD-ROM dri­ves can revert to using PIO mode, despite being set to use "DMA if Avail­able." Here's how to make Win­dows XP rede­tect the DMA capa­bil­i­ties of the drives.

This behav­iour occurs with the fol­low­ing conditions:

  • Win­dows XP is the oper­at­ing system
  • A CD-ROM or DVD-ROM drive, which is known to sup­port DMA mode now works only in PIO mode.
  • The drive con­troller is set to use "DMA if avail­able" but reports to be only in PIO mode.

Fol­low­ing is the mech­a­nism that has worked for me, please try it at your own risk, it involves hack­ing the registry:

  1. Open RegEdit
  2. Find the fol­low­ing KEY:
  3. The last four dig­its will be 0000, 0001, 0002, 0003, and so on.
  4. Under each key, delete all occurences of the fol­low­ing values:
  5. Reboot the com­puter. Win­dows will now rede­tect DMA settings.

Trala! If that doesn't do it, please check the very use­ful com­ment below by a user named STARK.

  • Nor­bert De Moor

    It really works!!! After hour of trial & error, installing IAA (and get­ting a very fast HD but no DVD/CDR any­more) edit­ing the reg­istry saved my day.

    Thanks for the help


  • McDon­ald

    Some of you may find the DMACHK util­ity from Microsoft use­ful for this pur­pose. There are use­ful notes on that web­site too.

  • Chris­t­ian

    I did it and it works
    I am now the most happy man on earth

    Thanks a lot for your help


  • GTP

    It works…

    Bet­ter: set Tim­ing­Mod­eAl­lowed for the spe­cific IDE drive to 0xffffffff. This will pre­vent the prob­lem from re-occuring again

  • snip­tools

    Thanks GTP, that's pretty useful!

  • Markx

    Thanks, this was very use­ful! You can also enable Ultra DMA 66 with a sim­ple such trick

    Edit the key


    and add a new DWORD value called EnableUDMA66 with a value of 1.

    Or, here save this as a *.reg file and exe­cute it

    Win­dows Reg­istry Edi­tor Ver­sion 5.00



  • Der Herrscher von Megara

    Thanks a lot for this hint. It saved me a lot of anger and frustration…

    Thumbs up!

  • Cow­boy

    Any of these tricks don't work with my com­puter :-( CD-ROM drive stays in PIO-mode.

    Any more ideas I could try?



  • snip­tools

    Hi Cow­boy, pls pro­vide details of your sys­tem. This lit­tle tip has worked for all friends (+ foes) who have tried it. –Shanx

  • Cow­boy

    Shanx, I have EPOX 8RDA3i moth­er­board (nForce2) and Samsung's DVD/CD-RW compo drive.

    I even tried to re-install Win­dows XP (and ser­vice pack1), but that didn't work either. With newest nForce2 chipset dri­vers I can acti­vate DMA from Device Man­ager for this sec­ondary IDE chan­nel, but when I put CD into drive my com­puter get stucked. It recov­ers when I took CD out!

    Seems that my compo drive is bro­ken or some­thing wrong in moth­er­board? BIOS set­ting should be OK.


  • shoN­uff

    Excel­lent. My DVD writer is back to prime time con­di­tion. What a dif­fer­ence! Went from 1.5+ hour burn time to 8 min­utes! Thanks a bunch for this post.

  • Jon

    Thanks for this. I was hav­ing major prob­lems with crappy DVD play­back which I found was likely to be a prob­lem through not hav­ing DMA enabled (drive was set to use DMA but was still using PIO).
    Done the edit, popped in a disc, and I had smooth play­back. Which was just as well cos it was start­ing to drive me up the wall.

    Many thanks

  • Net2u

    Another thing that worked for me.….switch the jumpers on the DVD/CD play­ers. I phys­i­cally changed the jumpers, so one is now the slave (instead of mas­ter) and the other player is now the mas­ter (instead of slave). This appar­ently forces the XP oper­at­ing sys­tem to reas­sign the DMA/PIO modes.

    Worked fine for me.


  • snip­tools

    Wow Bob, this is a really spiffy sug­ges­tion. I tried and this seems to work with Win­dows NT as well. Thanks!

  • rob

    Hi I'm using mem­o­ries to tv and keep get­ting burn prob­lems on the last album I cre­ate on the disc, I have enough space on the disc, I burn at 2 speed to douible make sure, do think this would help if I change it to DMA set­tings… com­plete new­bie here, where do I go into to find regedit?

    thanks for looking

  • joe­barr

    SuSE 9.1 will have DMA built in, so the cd and dvd writ­ing is sig­nif­i­cantly faster. Go linux! Here's a link to SUSE 9.1. Enjoy.

  • Alex

    You are a god, My box is work­ing at full speed now.

    Thank You, Thank You, Thank You!!!!


  • Ionut

    I tried some of these tweeks(getting DMACHECK from microsoft or edit­ing the reg­istry) and they worked fine at the first reboot.But after a few hours Pio mode is back.Any idee how to make the change to DMA irre­versible?
    I'm hav­ing prob­lems with my Asus CDRW on a ECSK7vta6 motherboard.

  • Doug

    Folks, am expe­ri­enc­ing same prob­lems but as a neo­phyte have a few quick ques­tions.
    First, where are you set­ting DMA modes for dri­ves from? BIOS? Or some­place else? In XP? I can't find the set­tings in the spe­cific drive prop­er­ties, or under Device Man­ager either on My Com­puter of Sys­tem. Where are the set­tings at?
    Also, GTP (1÷13÷04 post): where and how do I find the Tim­ing­Mod­eAl­lowed set­ting for the spe­cific IDE that you men­tioned?
    Finally, Net2u (post 3÷23÷04): when you switched jumpers on yr DVD and CDRW dri­ves, which dri­ver did you make the mas­ter, and which the slave?
    Thanks for all yr help, I'm too much of a neo­phyte to comftably edit the reg­istry unless I have to.

  • Josh

    Thanks, works well i can now copy a CD at a speed other than 3X… Cheers

  • snip­tools

    Hi Doug,

    The "DMA if avail­able" can be selected through the Device Man­ager in Win­dows XP and then right-clicking the IDE Chan­nels (your hard disks etc) to select the respec­tive Prop­er­ties. If you are not sure what you're doing, I strongly sug­gest read­ing up the man­u­als for your DVD/CD R/W first, or doing it with some­one present. There is a sim­ple intro at Microsoft. If you have a spe­cific ques­tion after this, ask away!


  • DavidB

    Same prob­lem, every once in a while. Why does it do that? I haven't done the reg edit, but will keep it in mind. A dif­fer­ent stroke that has worked for me was delet­ing the sec­ondary IDE dri­ver in hard­ware man­ager, then let WinXP (pro in my case) re-detect and re-install the dri­ver — comes back in DMA mode 2 (ATA33).


    Sys­tem: Plex­tor 708A DVDR/W & 4824A CDR/W on an ABIT KT7A-RAID mobo, AMD XP2400+ with 1.5 GB RAM and XP Pro.

  • Ste­fanK

    Great hint.…

    Saved me a lot of anger and prob­lems I was hav­ing with run­ning my burner at full speed.



  • Ran­dom

    If win­dows XP detects more than x num­ber of errors from a stor­age device it _permanently_ drops back the trans­fer method to a "safer" mode. A para­noid strat­egy like this may be jus­ti­fi­able for dodgy hard dri­ves with uncer­tain inter­faces or dodgy cabling but it's not good when it's trig­gered by a scratch on a CD/DVD, which it almost always is. Post 4 from GTP may be the solu­tion to this brain-dead fall­back scheme. You can find read errors recorded in the Event Viewer, BTW.

  • Ran­dom

    Actu­ally I was wrong: Post 4 from GTP isn't going to address the trans­fer method fall­back sys­tem; it's built into XP. Chang­ing Tim­ing­Mod­eAl­lowed will have no effect on this prob­lem re-occuring as XP will change this set­ting if enough errors are detected. Ques­tion: is there a reg­istry set­ting that con­trols the num­ber of read errors detected before XP will retard the data trans­fer method of a device??? If that was set to a very high num­ber, this prob­lem wouldn't occur in the first place. Any ideas?

  • Ran­dom

    Sorry for all these posts in a row. The Microsloth Noknowl­ege Base talks about this prob­lem here:;en-us;817472&Product=winxp. It basi­cally says "wait for the next ser­vice pack". Replace­ment ATAPI dri­vers are only avail­able through a man­ual request to MS sup­port (weird or what?!), and then you need to edit the reg­istry. BTW: VIA has it's own dri­vers but they cause Nero to fail burn­ing any DVD or CD on my com­puter (Epox 8KHA+ KT266A based m/b).

  • snip­tools

    Did not know that, Ran­dom, thanks for the info!

  • Kirk

    I have read all the infor­ma­tion about get­ting out of safe mode, but have tried every­thing and am unable to do so. I had some­one come to my place to fix my com­puter as there were viruses on my PC. He installed Adware and Nor­ton and there was some adware viruses that came up after scan­ning was com­plete. The rec­om­men­da­tion after I deleted some, but wasn't able to delete oth­ers, was to restart the com­puter in safe mode and try to delete them again. Now, my mouse is not work­ing and I'm only able to scan with Nor­ton, not Adware. Also, when I get to the menu to start the com­puter nor­mally or to go back to mscon­fig and des­e­lect safe mode, I'm unable to. Any sug­ges­tions??? Thank you.

  • John


    Down­load the KB824146 RPC worm patch for your ver­sion of Win­dows from Microsoft and the lat­est ver­sion of Stinger.exe from McAfee's web­site:(
    When while booted up in Win­dows, unhook your inter­net con­nec­tion and rein­stall Win­dows over­top of your cur­rent instal­la­tion which will keep all of your set­tings but revert you back to the SP level of your install CD. Then when your back up and run­ning again imme­di­ately install the KB824146 patch, reboot, run Stinger.exe to scan Drive C: then plug back into the inter­net and keep run­ning Win­dows Update over and over again to get back all of the crit­i­cal updates (bug fixes too, I'll bet…).

  • Ivve

    Hi all.
    I have prob­lems with my HItachi(IBM) Deskstar 120GB Hard­drive, Win­dows xp shows that the drive is work­ing in PIO mode even If I´ve cho­sen DMA if pos­si­ble, and I can­not change it man­u­ally, tried that reg­is­ter solu­tion and noth­ing hap­pend, tried DMACHECK.EXE and there the DMA was dsabled, I enabled it and rebooted and same shit again, PIO mode on the drive, what to do??? Please help. I´ve been try­ing to solve this prob­lem for a month now with­out any results.

    My comp. is:
    MSI k7N2-Delta moth­er­board.
    AMD 1700 XP
    512 DDR
    Geforce 4 MX 440
    Hitachi(IBM) Deskstar 120GB

    Please help me, I´ve gone bold now, tear­ing my hear of, this shit is dri­ving me insane. please please any­one help.

    Best regards, Ivve

  • Bag­gio

    Hi i use win xp and every time i open my pc autoexec.nt is missing.


    THANKS all for the infor­ma­tions about get­ting back to DMA mode in Win­dows XP.

  • jkue

    what you didn't say is, "After repar­ing win­dows I get this error mes­sage" yes, this occurs after repair­ing windows.

    A: There is another copy located in the \Windows\repair direc­tory, then again this may be empty after the reapir, look in the i386 folder for a copy of the file.

  • jkue

    … and place it here: c:\windows\system32\autoexec.nt

  • Bag­gio

    Thanks jkue but after a restart this file is miss­ing again.Every time i open­ning my pc i must copy this file from repair direc­tory to c:\windows\system32\?
    Another way?

    Thanks again.

  • jkue

    try dis­abling sys­tem restore, then copy the file there, now re-start. It should work.

  • jkue

    This should ele­vi­ate your prob­lem:;en-us;324767

  • Nic


    The mod cor­rupted Nor­ton Pro­tected Recy­cle Bin on all of my eight dri­ves, (using global set­ting).
    This was minor and eas­ily rec­ti­fied, I noticed the change after reboot straight away access if very fast.



  • Booze

    It works!


    Upon adding 2 new HDs to my sys­tem, W2K wouldn't run my 2nd slave (slave on IDE con­troller #2) in DMA even tho my 1st slave, same HD make/model, ran fine in DMA on the 1st IDE controller…

    Strange that the SlaveID was OK (it re-detected the same ID) but that Tim­ing­Mod­eAl­lowed was stuck at $10 (IIRC) instead of $ffffffff/all.

    Thank the Gods this thread was here! "4D36E96A!" Right! That's so obvi­ous! !*%$@#^ M$…

  • Booze

    Turns out I some­times have Event 9 (The device, \Device\Ide\IdePort1, did not respond within the time­out period) on that HD, which explains why W2k forced it back down to PIO-mode. The HD's in a remov­able cas­ing, prob­a­bly caus­ing some inter­fer­ence; I'll play w/ the cables and all and see what gives…

    Thanks again for the help.

  • Cstu­art

    I am hav­ing the same prob­lem chang­ing the DMA set­ting for my D: drive. It is all alone on the Sec­ond IDE chan­nel. I have tried the regedit deal and it did not work. I have the fol­low­ing set up run­ning Win­dows 2000.

    ASUS MB w/ AMD 1.33 GHz Proces­sor
    768 MB Ram
    ATI Radeon 7000
    Haup­pauge 250-MCE
    WD 20 GB HD
    Hitachi 250 GB HD
    Sound­blaster Live Value sound card

    How do I get the Hitachi 250 Gig on the sec­ond IDE con­troller to switch from PIO to DMA?


  • Mozzer

    I am tear­ing my hair out with hard drive stuck in PIO mode and so slug­gish it is unus­able.
    Same prob­lem with max­tor Dia­mond­max 9 160 Gb and HItachi Deskstar 250 Gb. Whether I place them as mas­ter or slave on pri­mary chan­nel.
    I have tried all reg­istry fixes, dmacheck, unistall pri­mary ide sev­eral times and even got hot­fix from MS which will not install on SP2.
    I even unistalled SP2 to run the hot­fix which then ran but did not fix the prob­lem.
    The basic prob­lem seems to be what­ever I do I still end up with atapi.sys dated 2001 and con­not update this any­how.
    Spent over 1 and a half hours on MS sup­port to no avail
    Sys­tem is:
    XP Home SP2
    Athlon 1.4 Ghz
    Moth­er­board Asus A7A266-E (lat­est BIOS)
    Graph­ics ATI Radeon 9200
    Mas­ter HDD Max­tor
    Slave HDD Hitachi Destk­star
    Both in pri­mary IDE with ultra UDMA 80 con­nec­tion round cable top of range belkin
    Jumpers all set appro­pri­ately.
    I've never been defeated by a PC prob­lem before but this one is dri­ving me to despair and I have wasted >2 weeks on it.
    Can any­ohne help please??

  • Bob

    Thanks, it worked and I am a very happy camper now.Thanks again

  • Richard


    Thanks for the reg­istry info. I have probs with Liteon SOHW633S dvdrw. I changed it to the mas­ter rom, but still using 100 cpu with any dvd edit­ing pro­gramme. One thing, the 2 reg­istry dele­tions in 0001 come back again on reboot ? dma seems OK, but on mas­ter prop­er­ties it says under device 01 that it's dma if avail­able — then cur­rent trans­fer mode = not applic­a­ble (shaded box). Is this right ? I'm XP, 512 ddr ram, 128mb nvidea 9200, 60gb hdd (45% used) Pin­na­cle tv 'rave' card.

    Any ideas please ? Many thanks.

  • Ashes

    Absolute leg­end thread. This prob­lem was killing me for a week until I found this.

  • Andrew

    It works!!! Thanks!!! I resolved my HDD — PIO only prob­lem. The XP SP2 sys­tem detected my sec­ond HDD as PIO. "Set­ting to DMA if avail­able" was no use. And even delet­ing the IDE con­troler dri­ver didn't work: after restart I had DMA, but when try­ing to write some­thing to the drive the sys­tem freezed and the PIO mode was set again.

    But your idea works! Thanks a lot! Now I have DMA on both drives! :)

  • Charles

    Thanks for the info, it worked like a charm. I started hav­ing prob­lems last night after i installed a slave HD on the sec­ond IDE. Was writ­ing in 1x/reading in 2x instead of 4x. Took the new HD out and was still slugish. Then noticed i was stuck in PIO, this was the sec­ond site i checked and found the answer Yay \o/

    IDE1= HDD + HDD
    IDE2= DVDWriter

  • Bob Downe

    Excel­lent reg hack — back to nor­mal! Thanks.

  • post8k

    When i change it, it works but the next day i turn on the pc its back with PIO. What should i do?

  • Rafael

    Thank you very much for your reg solu­tion, I was hav­ing this prob­lem for sev­eral days with my boot drive. Now is solved.

  • Mario


    Si fun­ciona, y fun­ciona muy bien

  • Jan

    I had prob­lems with the speed of my DVD drive and tried the trick men­tioned here with the regedit.

    I've been busy a week to get it going, now was done in 5 minuts.


  • Scott

    You're a god that deserves their own planet!
    Thank You very much for end­ing my agony.

  • Russ.R

    Many thanks to the writer of the reg.hack fix.
    My Plex­tor 708a started run­ning at a snails pace & I knew some­thing was not right with the con­troller set­ting but didn't know how to fix.
    Applied the reg. change sug­ges­tion, now drive is back up to nor­mal rip & burn speed.
    Once again a Big Thanks

  • Sam

    You are a LEGEND!!!
    2 OS rein­stall, sev­eral dvd shrink install / rein­stall, dif­fer­ent ver­sions and then you fix it with this info in 5 min. Thank you, thank you, thank you.

  • jesus_

    Well, it didn't work for me, can't get the DMA to work, it always sticks on PIO. Win XP on a P4 1.8GHz, msi mobo, noth­ing spe­cial, always worked in DMA mode untill a few days ago.

  • MJ

    A very BIG


    It really wokred for me now, no more crawl­ing speeds!!

    Thanks again!!!!

  • Greg

    hey all. it was asked before, and if it was answered i missed it. where do i find the Tim­ing­Mod­eAl­lowed to change it?

  • BN

    I have Hitachi Deskstar 120GB at work, and no mat­ter what I try it is in PIO mode. HDD is pri­mary slave. Pri­mary mas­ter is Max­tor and it work in Ultra DMA Mode 2.
    Com­puter is Dell Opteron, and Max­tor is orig­i­nal HDD in it.
    OS is Win XP SP2.

  • HoLa­BaLo

    Weee It really works!!!. After alll trou­bleshout it was so easy.

    /Many thanks

  • Hasan

    Does all these tricks work for enabling dma in my hard disk?

  • kent

    Does any­one know how to get a drive to work at the high­est DMA Mode it sup­ports? My drive sup­ports Mode 6 but it is set at Mode 2 in XP.

    Please help!!

  • DMA vs PIO

    Fixed HIGH CPU Usage when burin­ing prob­lem.
    It worked a treat on my Win­dows XP machine. I deleted all the val­ues as sug­gested, and then removed the Con­troller that had the CDROM drive on it from Com­puter Manager\Devices. I did a reboot and then it auto­mat­i­cally detected every­thing again and now uses only ~1% CPU when bur­ing instead of 40 – 50% CPU. The procexp.exe was a use­ful pro­gram for determing the cause of my high CPU prblem too.


  • hyc

    If your sys­tem uses an Intel chipset you can install the Intel Appli­ca­tion Accel­er­a­tor instead of the Microsoft IDE dri­ver. The Intel dri­ver gives you explicit con­trol over DMA modes thru a sep­a­rate util­ity pro­gram. I noticed one of my lap­tops run­ning really slowly, saw it was in PIO mode, and none of the other fixes worked. Unin­stalling the device and switch­ing to the Intel dri­ver made that prob­lem go away. The IAA is a free down­load from

    By the way, ver­sion 2.2 is the last one with explicit sup­port for Mobile (lap­top) chipsets, and it's too old to rec­og­nize the Cen­trino chipset. How­ever, I got the 2.3 dri­vers to install on my lap­top by adding some entries to the driver's .INF file. The i855 chipset has an 82801DBM IDE con­troller, and the dri­ver only rec­og­nizes 82801DB. But accord­ing to the datasheets, 82801DBM and 82801DB are func­tion­ally equiv­a­lent, so it's a safe mod.

    To install — run the setup pro­gram with the "-A" switch which just copies the dri­vers onto "C:\Program Files\Intel\Intel Appli­ca­tion Accel­er­a­tor" with­out installing them. Then go into that direc­tory, in the Win2K_XP direc­tory, and make a backup of the IdeChnDr.inf file. (You may want the orig­i­nal in case you screw up the mod.)

    The device iden­ti­fier for the 82801DB is already in the inf file, "PCI\VEN_8086&DEV_24CB". You need to add the ID of the 82801DBM, which is "PCI\VEN_8086&DEV_24CA".

    You have to add 3 lines to the inf file:

    at line 38 insert this:

    at line 79 insert this:

    ; ICH-4M — 82801DBM
    %PCI\VEN_8086&DEV_24CA.DeviceDesc%=IdeBusDr_Inst, PCI\VEN_8086&DEV_24CA

    at line 151 insert this:
    PCI\VEN_8086&DEV_24CA.DeviceDesc="Intel® 82801DBM Ultra ATA Controller"

    Then go into the Device Man­ager, under IDE ATA/ATAPI con­trollers, and update the dri­ver for the Ultra ATA con­troller that's already there. Select "Install from a list or spe­cific loca­tion", / NEXT, then
    "Don't search…" / NEXT, then
    Have Disk, browse to the Intel\…\Win2K_XP direc­tory to make it load with the Inf file you edited.

    Don't restart the com­puter, fol­low the same pro­ce­dure to update the dri­vers for the Pri­mary and Sec­ondary IDE chan­nels on this con­troller first, and then restart.

  • Hubert Yun

    Hi guys. I fol­low the direc­tions above and delete every occur­rence of Mas­terId­Dat­aCheck­sum and SlaveI­d­Dat­aCheck­sum under the cor­rect key, but it is not work­ing. In fact after I reboot, Mas­terId­Dat­aCheck­sum and SlaveI­d­Dat­aCheck­sum are back in the reg­istry under the same key. Am I doing some­thing wrong? I have a fairly new Dimen­sion 3000. I just added a sec­ond hard drive as a slave on the pri­mary and it is show­ing PIO. My CD-Rom is also a slave on the sec­ondary and will not change out of PIO. Any help would be great. Thanks.

  • Colin99

    Not just CD/DVD but hard disks too. At last my machine doesn't hic­cup and pause every time the HDD light comes on, it's back on DMA rather than PIO for the Pri­mary IDE Chan­nel. I was close to replac­ing the machine but for this! Win­dows XP, VIA chipset with RAID.

  • The Unbe­liever

    Had a prob­lem with my HDD in Win­dows 2000…
    Your trick did it thing.
    Big thanks, man. :)

  • Doug

    None of this worked for me but chang­ing the ide cable did ! The old cable had tight bends and kinks from a poorly refit­ted hard drive. ( not by me ! ) Gone from some­times mode 2 to mode 5
    I have a 40 gb hd mas­ter and a 120 gb hd slave.
    DVD/CD was ok

  • Ted

    I'm using a pre­sario 2000 with xpsp2. My pri­mary drive won't go into dma. I tried the regedit and when I rebooted the com­puter hung at the blue win­dows xp screen. Had to refor­mat and start over.

    After refor­mat, the drive was in DMA for about 3 days and then slipped back into pio.

    Before I try the regedit thing again (maybe I screwed it up some­how) did any­one else expe­ri­ence a fail­ure to boot into win­dows prop­erly after­wards but me?

    Ques­tion 2 — One sug­ges­tion to regain dma mode is to unin­stall the dri­ver for the pri­mary ide drive and let win­dows rein­stall it when it boots up. My ques­tion is — will the drive still work prop­erly dur­ing the boot process until win­dows re-installs the dri­ver? I've done this on sec­ondary devices but never pri­mary — I don't want to do some­thing stu­pid and have to refor­mat again!

    Thanks so much for any help on this great web­site that I recently dis­cov­ered (com­paq sup­port actu­ally told me about it!)


  • Justin

    keep get­ting drive time out errors, not block errors. any idea what this actu­ally means?

  • Olivboy

    Great post! Worked 4 me 2 on XP.

  • Net2u

    Remem­ber this trick: Try switch­ing the jumpers on your disk dri­ves. My com­puter has a dvd recorder and a sep­a­rate dvd/cd player. Just change the jumpers on them. Make the other one the mas­ter and the remain­ing device a slave. This appar­ently forces XP (and NT) to reas­sign the DMA/PIO modes. It worked for me with­out chang­ing the registry.

  • Nor­ton Tech.

    Couldn't get this work­ing on a Dell Opti­plex GX270. After check­ing the BIOS I found the drive was selected as 'OFF', though XP could still use it. Turned it on and UDMA5 access is enabled.
    BTW can't use Intel Appli­ca­tion Accel­er­a­tor on this PCs chipset (865GV) — it's not supported.

  • fel­low sufferer

    and another point:
    I did all the above to fix my pri­mary drive — good stuff (don't later do the rough fix of delet­ing the IDE entries in Device man­ager as it puts back the Dat­aCheck­SumId you care­fully removed with regedit)

    Now the tip:
    I have a sec­ond inter­nal hard drive — I orig­i­nally bought it to put in an exter­nal usb box but it ran like a sick dog so one day I just put it inside the pc

    instant improve­ment but the slave drive shows as PIO mode, while the mas­ter drive shows Udma6

    Much fid­dling with jumpers, reset­ting all the above etc etc — PIO mode still

    Then light goes on in head: the damn BIOS had Pri­mary Slave set to Off — so check that DMA is enabled at BIOS level on sec­ondary dri­ves — bliss

  • gabby

    For dell com­put­ers try clear­ing the nvram. most dell com­put­ers has a one page bios. to enter the bios tap "f2" when you see the dell logo. once in the bios turn all the light of your key­board on…"numlock, caps, scroll"…Press ALT+F, ALT+E, then ALT+B…this will restart your sys­tem and per­form an auto­matic ide configuration.

  • Sol­stice

    This page is a great find — but did not resolve the issue for my WD 160Gb though.

    I only decided to check my drive after a co-worker asked me how to speed up his machine — I told him to check the dma mode — his was in PIO and the sim­ple tog­gle to PIO then to DMA brought his drive to the right mode. This did not work for my drive. I then deleted MasterIDCheckSum(and slave) and rebooted. This did not work. Changed the other keys men­tioned in this article(and links) rebooted — not work­ing. Switched to Stan­dard Dual Chan­nel IDE dri­ver from M$, then reloaded my ALI IDE Dri­ver and then changed back to the ALI IDE Dri­ver — still not work­ing. Down­load WD WinDLG pro­gram to test drive and all tests Pass. Call WD Tech sup­port. They sug­gested dou­ble jumper­ing the drive and set bios to auto with LBA. The bios rec­og­nized as a 32Gb in auto mode, still hav­ing prob­lem. Pre­vi­ously was using CHS 1023÷16÷63 with LBA, bios picked up as 528Mb and have DDO installed — Dynamic Drive Over­lay to trans­late the full size to XP) WD Sup­port said long term solu­tion was to use a con­troller card ide instead of BIOS IDE, but sent me advanced WD sup­port to see about get­ting drive back into DMA before get­ting con­troller card to ensure no prob­lems with drive itself. When talk­ing with advanced WD sup­port (con­dasend­ing A$$wipe) as soon as I men­tioned XP this guy assumed I know noth­ing about a computer.

    Long story short, my drive was in DMA until Feb 6th(I just noticed prob­lem last week) the event log has 7 alerts with time­outs after every reboot start­ing the 6th and until dis­cov­er­ing my prob­lem the reboots were just a few. Now when I reboot the machine pauses and when I look in event­log there are 7 time­out alerts. Hope­fully a con­troller card will resolve my problem.

    Oth­er­wise the info posted here should work for 95% of the peo­ple expe­ri­enc­ing this prob­lem. It did for another HDD and my CDRW.

  • vamps_2

    Hi Sol­stice you just took the words right out of my mouth! I can relate almost exactly to what you are and have gone through with you PC I like you have tried all of the above and God knows what else I have Win­dows XP pro and have con­tacted Microsoft Sup­port and have not really had a res­o­lu­tion to Reset­ting DMA Back to Ultra Mode5 in Cur­rent Trans­fer Mode Device:0 which was the set­tings the Pri­mary Chan­nel was in about 3 weeks ago! go fig­ure any­how what exactly does a Con­troller Card do, I would like to look into a Con­troller Card if that resolves this DMA reset­ing issue.I have unin­stalled Pri­mary Chan­nel and Sec­ondary Chan­nel was able to reset Sec­ondary Chan­nel back to Ultra Mode2 so that is good now it's the Pri­mary Chan­nel that is stuck in Cur­rent Trans­fer Mode PIO ,by default I can­not unin­stall IDE/ATA/ATAPI con­troller as was sug­gested in DVDD forums so I unin­stall Pri­mary and Sec­ondary Chan­nels it's worked before just not any­more:(

  • Ricky

    I deleted the Pri­mary IDE chan­nel in hopes of on reboot on would be able to select DMA and speed up burn­ing on my I/O magic burner. How­ever when I deleted the pri­mary IDE chan­nel i believe it con­trolled the os which is on my hard drive and now when try­ing to reboot I just get the dell logo and it just loops over and over back to the dell logo. I can­not even boot up the xp cd. My hard dri­ves (2) are on cable select I will try to change one to mas­ter and one to slave to see what hap­pens but in the mean time I would like any sug­ges­tions for get­ting my sys­tem to boot up properly.

  • vamps_2

    Hi all well I down­loaded and ran the setup.exe file tune­upXP 1.5 from Web­page I then fol­lowed the guide­lines from can find Get­ting Back To DMA Mode then I went into Device Man­ager and Under IDE/ATA/ATAPI CONTROLLER : pri­mary chan­nel I went into advanced set­tings and in the TRANSFER MODE :DMA if avail­able .…… I changed it to PIO MODE if avail­abe I did the same pro­ce­dure in the SECONDARY CHANNEL .….. I then scanned for Hard­ware changes in (Device Man­ager) .….….……So I recre­ated the same pro­ce­dure but this time in the Advanced Setting/Transfer Mode it read : PIO MODE if avail­able the same was for the SECONDARY CHANNEL Trans­fer Mode: PIO MODE if avail­able, I then changed the Mode back to DMA if avail­able in Transer Mode in both Chan­nels and scanned for Hard­ware changes in Device Man­ager. And just like magic there it was

    Device 0: auto­matic
    Trans­fer Mode : DMA if avail­able
    Cur­rent Transer Mode: ULTRA DMA5

    Device 1: auto­matic
    Trans­fer Mode: DMA if avail­able
    Cur­rent Trans­fer Mode : ULTRA DMA2

    One thing I did learn is to not unin­stall the Sis PCI IDE Con­troller (at least not in my Com­puter) since it caused mal­fun­tion and Win­dows started to Shut­down and restart on it's own Spon­ta­neously, some­thing to do with the mini­port dri­ver any­how I did have to rein­stall a fresh Copy of Win­dows XP sad­fully but not regret­fully so now I have begun a much more knowl­edge­able and Enligh­t­end Jour­ney in the World of DMA Trou­ble Shooting .

    P.S Google Search has some really good
    resources also

    sin­cerely vamps_2

  • Roody­pooh

    The Dell advice that Gabby gave was bang on. Remember…just because Win­dows recon­g­nises your dri­ves doesnt mean your bios does.

    In the Dell Setup hit:(with CAPS,NUM and SCROLL lit):

    It will then do the auto­mi­atic IDE con­fig­u­ra­tion and presto!!

  • elvin has instruc­tions for peo­ple who are hav­ing PIO per­for­mance issues with A7A266-(E) motherboards.

  • Yodamann

    Kicka__s! What a fix! Thanks!

  • gman312

    Rather than screw­ing around with the reg­istry, I decided to fol­low Roodypoohs's tip. What a lifesaver!

    I pur­chased a Max­tor 300 GB HD with 16 MB cache two months ago for a major video-editing project and to my amaze­ment it per­formed like a dog (I am also using a WD 250 GB and a Max­tor 120 GB HD for this same v/e project).

    I tried every­thing I could think of w/o suc­cess. In des­per­a­tion I came to this board and real­ized there were oth­ers like me with sim­i­lar issues. I get a lit­tle edgy when it comes to reg hacks, so I took a more con­ser­v­a­tive course and fol­lowed Roodypooh's advice. I can't thank Roody­pooh enough.

    Best of luck to oth­ers in a sim­i­lar fix!


  • nethawk

    none of these tips worked my hard drive stays in PIO mode any other suggestions

  • snip­tools

    Nethawk, it'd be use­ful to have more infor­ma­tion about your hardware.

  • nethawk

    ECS K7SOM+ mobo
    AMD Athlon XP 2200+
    Hitachi Deskstar 40Gb

  • Sebas­t­ian

    Your ROCK man, this is very use­full infor­ma­tion, thanks and god bless you

  • Stark

    nethawk, and any­one who can't enable DMA mode on your hard disk con­troller, do the following:

    To enable DMA mode using the Device Manager

    1. Open Device Manager.

    2. Double-click IDE ATA/ATAPI Con­trollers to dis­play the list of con­trollers and channels.

    3. Right-click the icon for the chan­nel to which the device is con­nected, select Prop­er­ties, and then click the Advanced Set­tings tab.

    4. In the Cur­rent Trans­fer Mode drop-down box, select DMA if Avail­able if the cur­rent set­ting is "PIO Only."
    If the drop-down box already shows "DMA if Avail­able" but the cur­rent trans­fer mode is PIO, then the user must tog­gle the set­tings. That is:

    • Change the selec­tion from "DMA if avail­able" to PIO only, and click OK.

    • Then repeat the steps above to change the selec­tion to DMA if Available.

    I got this from Microsoft web­site. I also couldn't enable DMA on my hard disk con­troller after upgrad­ing from WinME to WinXP SP2, but that DID work.

  • netfx


    that one really works (although seems point­less at first)… I have had this prob­lem for awhile with my UDMA acti­vated hard drive always show­ing up in PIO mode, yet doing what Stark sug­gested sorted out my pc when all of the other sug­ges­tions in here did'nt achieve anything.

    What I did was to change IDE0 (hard drive) and IDE1 (CD) back to PIO/NONE (no auto detec­tion)… and hit accept and close that win­dow. Then open IDE0 prop­er­ties again and lo and behold the DMA WHEN AVAILABLE option was vis­i­ble in the small drop down menu.

    I selected this and then accepted and closed the prop­er­ties win­dow once more. Then I reopened the IDE0 prop­er­ties again and there it was… "UDMA4". Rebooted, checked again and yep… still in UDMA4 mode.

    Next I went to the IDE1 and reset auto detec­tion but left the CD in PIO mode (just in case it sent me back to square one). I dont mind hav­ing the cd in PIO but run­ning my hard in PIO was just plain sukky.

    Many big thanks to STARK, the eas­i­est and best answer so far on this DMA/PIO prob­lem. (I just wish Starks answer was at the top of this forum so that I would have tried his sug­ges­tion first instead of the more risky reg hack­ing reg and delet­ing hard drive controllers).

  • Eye­sWideShut

    Hi all,

    I have tried all the meth­ods, but no luck. It doesn't work. I have even tried the DMACHK util­ity and it shows Enabled when I reopen it after the restart, but it still says "DMA not in use" as it is also shown in the Advanced Set­tings [PIO Mode].

    My sys­tem is:
    AMD Athlon 2500+
    512 mb ram
    128 GeForce FX5600
    120 gb Sea­gate hard drive

    The prob­lem is in my hard drive. I have already removed the dvd burner. Don't know what else to do. Now down­load­ing SP2, if that might help.

    If any­one can help, I would be grate­ful forever.



    I have a sit­u­a­tion were the DVD will not play nor can the PC 'see' a photo cd pro­duced by a photo shop but the cd burner will 'see' data and also burn new data onto cd-rw/cd-r. This infor­ma­tion on DMA — will it solve my sit­u­a­tion?
    The IDE is in PIO mode oth­er­wise I do not see any prob­lems with oper­a­tions with appli­ca­tions or email.

  • Rajka­mal

    Hi, thanks a lot. it worked for me. my drive is sam­sung and it worked as u said. good work. thanks buddies.

  • Szy­mon

    I had this nasty DMA prob­lem on my IBM Thinkpad T41. It came out when I tried to test a freshly-burned DVD by copy­ing its con­tents to the hard disk. It was so frig­ging slow and the machine got so unre­spon­sive that it drove me crazy.
    I found noth­ing help­ful nei­ther on IBM nor Microsoft sites. Then I came to this page and the solu­tion described here solved my prob­lem indeed!

    Thanks a lot guys!

  • Curt

    Wow! I have suf­fered for months with a butt-slow Stinkpad T30 and it's now back to the way it should be with a ONE-MINUTE FIX! You folks are the great­est!
    Thank you, Thank you, Thank you!

    Curt Hayes

  • Tonio

    THANKS. It worked. I can now see a DVD on my Insp­iron 9300 with­out becom­ing sea sick!!!

  • Dan

    I hope this is not off topic but I have a prob­lem with a LG GDR-8163B dvd-rom. The thing is that it can­not copy the cd(or dvd) con­tent while in dma mode so I had to force it to use PIO mode as described ear­lier on this page. When in dma mode it reads the cd TOC because I can see the files but I can­not copy them but in pio mode works per­fectly only that it keeps my cpu (AMD Sem­pron 2200+) at 100% (this is nor­mal in pio mode). This is why I want to knopw if there is some­thing I can do to make it work in dma mode. I've also checked the producer's site for a firmware upgrade but didn't find one.
    Than you,

  • Bob

    Thanks a lot! Every­thing works now.

  • Luca

    After hours of search and tri­als I found your mes­sage and now it works!

    Thanks a lot!!!


  • Kolo

    After sev­eral attempts i man­aged to turn on DMA on both CD an HDD.
    It worked after delet­ing:
    And set­ting Tim­ing­Mod­eAl­lowed to 0xffffffff as described by GTP.
    Delet­ing only Mas­terId… and SlaveId… did work only for cd…

  • Simon C-S

    I have also had dis­tinct and frrus­trat­ing time get­ting both the pri­mary IDE (2 HDDs) and sec­ondary (2 DVD writ­ers) to run in DMA mode. All 4 would only run in PIO mode. I tried the reg­istry, dmacheck and remove/redetect sec­ondary IDE chan­nel meth­ods, and noth­ing worked.

    What *DID* work was updat­ing the dri­ver from ATA to Stan­dard Dual IDE con­troller. Once this was done, all 4 dri­ves came up show­ing as run­ning in DMA mode. What a relief that was.

    The other tip I've seen is to check for "Allow PCI Bus Mas­ters = Enabled" in the BIOS.

  • Robo

    Ok I can get DMA to work OK,,,,,,,,, but my mas­ter & Slave are both rated to work at DMA 5,,,,,,,,but the lit­tle suck­ers will only run at DMA 2 for the mas­ter and DMA 1 for the Slave.
    This is on a XP pro sys­tem with a VIA Apollo chipset.Any sug­ges­tions on how to get the two do-hickies to run at DMA 5?

  • Justix

    I have almost the same prob­lem using a DELL Opti­plex 170L where a new DVDR DUAL GO W1616B refuse to go DMA and it cause me prob­lem in burn­ing data backups.

    I did almost every­thing I could like rreg­istry tricks delet­ing IDE chan­nels ect..but no way of hav­ing this lat set on DMA, the DVDR is set as slave on IDE1 while on mas­ter I have a CDR which is actu­ally set on DMA 2, the cable doesn't look to be an 80 pin one more like a ordi­nary IDE cable, would that be the prob­lem? if so why is the CDR ( which is def­i­nitely older than the device I'm try­ing to make work) work­ing with DMA and the DVDR not?

    Will swap­ping the DVDR on Mas­ter make any dif­fer­ence? Or should I try to check for a 80pin cable? The bios set­ting for the IDE chan­nel got DMA on ,but the DELL bios does suck a bit not leav­ing me much changes I can operate

    Won­der if the DELL trick sug­gested by gabby will work for me. …desperate : (

  • Veiga

    Well, I tried exhaus­tively the STARK / Microsoft trick and it DIDN´T work for me. I even
    tried to change it to PIO, reboot, then change it do "DMA if avail­able" and reboot and I was not able to make it work at all!

    Then I’ve tried the Regedit trick and it worked GREAT!!!!! Now my Max­tor Dia­mond Plus 9 6Y120L0 is work­ing on UDMA6 mode!

    Thanks !!!

  • lamff

    Another use­ful site from MS -

  • Mary

    I tried every­thing that was posted in this log. The only thing that finally worked for me was to install ide con­troller that was not listed in the chipset's update. I am run­ning
    Pen­tium 3
    Xp Pro , sp2
    PCChips, M756mrt
    SIS 630.
    Do a search on side213.exe for the only dri­vers that have worked. I was also able to shave 13 sec­onds off my boot time, and have DMA mode 2 on all 4 dri­ves (at least it's bet­ter than PIO)

  • Mary

    The above file should be sis202 to enable SIS Mini PCI IDE (Ultra DMA. It is spe­cific for xp and Win 2000 with chipsets ATA 133

  • Fritz

    Thanks to the post by fyc about the Intel Appli­ca­tion Accel­er­a­tor!! Noth­ing else worked for me excep for this. I just dowloaded it and installed it from intel with­out the mod­i­fi­ca­tions sug­gested by fyc and it worked great. Using the other sug­gested fixes I was able to get DMA work­ing on my mas­ter drive but noth­ing else would get my slave drive into DMA mode except for the Intel dri­vers. Spent all day on this darn thing. Thanks to all !!!

  • Dav­ester

    My solu­tion was to open device man­ager, unin­stall the pri­mary ide chan­nel, which was only run­ning pio, then restart. The com­puter found and rein­stalled the ide chan­nel, I restarted again and holy mac­a­roni it works. Hope this helps some­body. Now if I could just get 'em from dma mode 2 to mode 5.….…

  • bob

    Thank you Snip­tools and every­ones com­ments. my wifee's com­puter can read dvds again after count­less times try­ing to tog­gle back and forth from PIO mode. I nearly gave up, so glad I found your wis­dom. Thanks again.

  • motix

    Hi all,

    Some­times can help the fol­low­ing procedure:

    Set the fol­low­ing reg­istry key

    1 — enable mas­ter DMA
    2 — enable slave DMA
    3 — enable master/slave DMA

    To choose the proper "Scsi Port N" (N can be 0,1,2, …) take look inside

    HKLM\HARDWARE\DEVICEMAP\Scsi\Scsi Port N\Target Id 0\Logical Unit Id 0\Identifier

    If Iden­ti­fer con­tains the name of your CD than you find the cor­rect N.

    Thi pro­ce­dure helped me to RETURN back the DMA mode on my DVD/CD RW combo drive.


  • Barry

    Have a Dell XPS3 with 2SATA hard dri­ves, and two DVD-rw on pri­mary ide. One day the slave sata drive, and the mas­ter dvd both would only work in pio. The reg change fixed my dvd, but can't for the life of me find where the entries are for the sata dri­ves. The Bios fix didn't do any­thing. Do I unin­stall the Intel 82801FB/FBM Ultra Ata Con­troller, or the Intel 82801FR SATA AHCA con­troller? Will my puter reboot with­out these?

  • Eduardo

    Thanks a lot. It worked for me. My dvd writer was writ­ing at 1x and using all the pc resources. I have the impres­sion that if the XP finds errors while read­ing (writ­ing) dvds, it will turn pio mode back again. Microsoft should fix that. I don't know any­body who wants to use pio mode anymore.

  • Suvik

    Man! Thank you very much. I would've never fig­ured out what to do with this stuff. It turned out to be so sim­ple. Sim­ple if you know what you're doing, that is. Thanks again.
    Alex Suvik

  • Pass­mas­ter

    My pri­mary IDE HDD was put in PIO mode by Win­dows XP — I tried the trick of chang­ing the set­ting to PIO and then going back to DMA if avail­able but it did not work. The thing that worked for me was to Unin­stall the dri­ver and reboot. On the first reboot win­dows will detect the "new" hard­ware and after installing the dri­ver will ask you to reboot again. After the sec­ond reboot the HDD was cor­rectly put in Ultra DMA Mode 5

  • Ram

    I have a Dell Opti­plex GX1p, with Win­dows XP pro­fes­sional with SP2. I tried to upgrade my hard drive to a 250 GB Hitachi Deskstar. The Setup does not even rec­og­nize the drive using "Auto" detect, and I can't man­u­ally set the drive to specs. Any sug­ges­tions?

  • Vis

    Reg edit worked! Yip­pie!
    Hours of hard drive test­ing.. showed noth­ing.… I have a sam­sung HD and a dell 1100 desk­top. Tryed dell bios. no effect. tryed swith­ing back and forth no effect. My big ? now is will it hold?

    The rea­son accord­ing to win­dows log is 3 or more errors in HD cause DMA lock out.

    Yet drive shows good?! Very good now DMA %5 !

    But will it hold. You know dell is now mount­ing dri­ves ver­ti­cal!
    stright up in air! must have some effect.

  • JD

    Wow!! Hyc's com­ment regard­ing Intel chipsets was the best solu­tion to my per­for­mance prob­lems. Kick out that crappy default dri­ver shipped with Win­dows and put in the Intel's updated dri­ver and my sys­tem is hum­ming now (and the Cen­trino trick for lap­tops works!). Thanks so much for this great solu­tion. Oth­ers might want to try it as it obvi­ates the need for even deal­ing with the Reg­istry edits or MS funny non-intuitive tog­gle junk.

  • Flash_back

    Thanks a lot!! With the post of Stank i solve it!!.
    But the only prob­lem is that i can't set the hard drive to DMA MODE 5.
    Any­body knows how set the drive to dma mode 5?.

  • Jacque­line

    Famil­i­air prob­lem that is men­tioned here. I bought a new Max­tor 250GB HDD and it would only work in PIO-modus. Rein­stalling XP didn't work. I flashed my BIOS but that didn't make a dif­fer­ende either. I tried every pos­si­ble option that was men­tioned here,but noth­ing worked. Fur­ther search on the Inter­net pro­vided me a page that DID help me.

    I have an ASUS A7A266 MB and this MB seems to have a prob­lem with large HDD's. So, I wasn't alone, thank God! 😀 This is the URL to that webpage:

    I installed the updated dri­ver and fol­lowed the instruc­tions in the README.TXT file. And, holy crap…It WORKS!!! Finally, after days of going crazy and almost throw­ing my PC out of the win­dow, my HDD's are work­ing fine now.

    Notice: If you see these two IDE con­trollers become "SCSI/RAID Host Con­troller" in Win­dows "Device Man­ager", this is nor­mal, don't worry. Since "ALi Ultra IDE Dri­ver" is used to mimic IDE devices as SCSI devices. There­fore you will find your IDE devices becom­ing SCSI devices in "Device Manager".

    Well, if you have the same MB, please visit the site I men­tioned if all the above doesn't work. Good luck with it!

    Gr. Jacque­line from The Netherlands.

  • Jacque­line

    All the above didn't work for me…But what DID work, was installing another dri­ver for my MB. I have an ASUS A7A266 MB and it seems to be a famil­i­air prob­lem that this MB has prob­lems with detect­ing large HDD's

    My 250GB Max­tor HDD stayed in PIO-modus, no mat­ter what I tried. I flashed the BIOS, rein­stalled XP, tried all of the above but noth­ing worked.

    After surf­ing around on the Inter­net I found a site that helped me out. It seems I can­not post the link here because that is seen als spam :( Well, what I did was down­load: ALi's Ultra­IDE dri­ver, ver­sion

    I fol­lowed the direc­tions in the README.TXT file…I was told to notice: If you see these two IDE con­trollers become "SCSI/RAID Host Con­troller" in Win­dows "Device Man­ager", this is nor­mal, don't worry. Since "ALi Ultra IDE Dri­ver" is used to mimic IDE devices as SCSI devices. There­fore you will find your IDE devices becom­ing SCSI devices in "Device Manager"

    And, holy crap…This WORKED!!! Finally, after days of going crazy, both my HDD's are work­ing fine now and at nor­mal speed.

    So, if you have a MB using an ALiMagik 1 chipset, such as the Asus A7A266, or Asus A7A266-E and you have prob­lems with a large HDD…install the dri­ver I men­tioned. I hope it will work for you as well.

    Good Luck!

    Greet­ings from Jacque­line from The Netherlands.

  • Andy

    This thread saved my life — thanks guys.

    I've got an Advent T9303, Intel 82801 etc. chipset, 2 x Sea­gate ST3200822AS dri­ves (SATA), WinXP Home SP2. Every so often, one or other would fall back to PIO mode, and the only fix I'd found until I dis­cov­ered this site was to re-install XP (and then every­thing else…).

    FWIW, none of the SCSI DMAEn­abled, the IDE trans­fer mode or the unin­stall dri­ver tricks worked, but the orig­i­nal trick of delet­ing the check­sums did. A small note, they weren't in ../CurrentControlSet/.. but in ../ControlSet001/.. , ..002, etc. (in case anybody's lost them!).

    Inter­est­ingly, after the last re-install, I had no prob­lem for over a month (a record for this heap-of-trouble PC). Then I remem­bered I hadn't done a Win­dows update (and auto­matic update was off), so off I went to get the updates (you can see it com­ing, can't you!). Within a cou­ple of days — severe crash, blue screens all round, PIO mode when I even­tu­ally got it to reboot. So, it would appear the prob­lem is with one of the 30+ updates — any ideas?

    Thanks again to all contributors.

  • WTL

    It really works ! Thak you !
    I have a 160GB Sea­gate Bar­racuda. I sus­pected my com­puter doesnt want to coop­er­ate with it because of 127GB limit prob­lem…
    You saved my disk from throw­ing it away 😉

  • Lin731

    Here's some specfics on clear­ing the nvram (for Dell Users)

    Clear the NVRAM on Dellâ„¢ Dimen­sionâ„¢ 1100, B110, 2200, 2400, 3000, 4300, 4500s, 4600, 4600c, 4600i, 8100, 8200, 8300, 8300n, XPS, XPS Gen2, XPS Gen 3

    To clear the NVRAM, per­form the fol­low­ing steps:
    Restart your com­puter.
    At the first text on the screen or at the Dell logo, press the key every three sec­onds until the mes­sage Enter­ing Setup appears.
    The Sys­tem Setup screen appears.
    Press the key, the key, and the key to light up all three lights on the key­board.
    Press the and keys at the same time.
    The sys­tem will emit a beep tone to indi­cate that NVRAM has been cleared.
    Press the key, and then press the key to save the changes and reboot the sys­tem.
    Pro­ceed with the instal­la­tion or trou­bleshoot­ing that you were attempting.

    You can find all the specifics for each sys­tem at Dell sup­port.. I'd post the link but appar­ently that's a "nono". If you do a google search with the phrase " How Do I Clear NVRAM on my Dell Dimen­sion Sys­tem?" it should pop right up with a link. Prob­a­bly will for their other mod­els too.

    Gabby thanks for point­ing me in that direc­tion. I don't know if it will work but if it does, it's a MUCH eas­ier fix than mess­ing with reg­istry edits, mod­i­fy­ing Bio's or hotfixes…I'm leery of even attempt­ing those, given the dam­age you can do if you mess up. I'm not THAT tech savy.

  • Trendy Kinda Guy

    PIO detected on Sam­sung MP0402H. I know this needs to be in DMA and I'm not sure how to get it there? I'm afaid to screw up my com­puter as well.

  • Trendy Kinda Guy

    also, my Pri­mary chan­nel will not change using STARK's tech­nique, but Sec­ondary chan­nel will…

  • Trendy Kinda Guy

    Geez… i keep for­get­ting to tell this…

    My lap­top is a Dell Lat­i­tude D610

    It's mainly used for record­ing and the issue is with the record­ing inter­face. A Line 6 Tone Port UX1

  • Henk

    My QSI DVD-ROM SDR-081 in my SONY VAIO PCG-FX501 decided that now it only reads DVD's and no more CDROM's or AUDIO CD's. I checked my IDE set­tings but both chan­nels are in DMA. I unloaded, decon­nected, and had Win­dows XP rein­stall to no avail. Any­one any idea/solution?

  • Larry

    I'm hav­ing the same prob­lem, Henk, after an inva­sion of my PC, due either to hack­ing or a tro­jan. Any sug­ges­tions on fur­ther advice?

  • Larry

    Sorry, should have been more spe­cific about my sit­u­a­tion. Turned on my PC one morn­ing and sud­denly the Guest account appeared. I tried to shut it off, but could not ini­tially (ini­tially I learned how to). Mean­while, the Guest account was full of porn in its his­tory folder.

    My user account (I share this PC with another per­son, and we each have pass­word accounts, thank god) was no longer an admin account.

    Many prob­lems have resulted from this. I want to refor­mat the PC and start clean, but I cre­ate orig­i­nal video mate­r­ial for my job, and much of it is on my PC only (other stuff is backed up, but unfor­tu­nately I wasn't always that good about that). I want to burn this mate­r­ial to DVD before I reformat.

    I can't. One thing that hap­pened in this inva­sion is that DMA was turned off. I can't fig­ure out how to turn it back on. I've tried the meth­ods listed here.

    Here's what MyDVD tells me:

    MyDVD has detected that DMA is turned off from one or more of the record­ing devices attached to the sys­tem. In order to suc­cess­fully write to the device, DMA should be turned on, refer to your oper­at­ing sys­tem man­ual or use Win­dows Help for instruc­tions on how to do this."

    I looked at my advanced set­tings per this thread and here's what I got:

    Device 0
    Device type: Auto Detec­tion (this is greyed)
    Trans­fer Mode: DMA if avail­able
    Cur­rent Trans­fer Mode: Ultra DMA Mode 2

    Device 1
    Device type: Auto Detec­tion
    Trans­fer Mode: DMA if avail­able
    Cur­rent Trans­fer Mode: Not applicable

    I'm not a PC per­son so I don't really even know how to begin solv­ing this prob­lem. Any sug­ges­tions would be greatly appre­ci­ated. Thanks.

  • dom

    Even sim­pler way to solve the PIO/DMA prob­lem. I have found 9 out of 10 times works — just Unin­stall whichever IDE chan­nel is caus­ing the prob­lem (usu­ally the sec­ondary) with a right-click in Device Man­ager — then reboot.
    The DMA will be re-installed cor­rectly, and all will be well. Not usu­ally any need to fid­dle w reg­istry.
    this is a well known 'fea­ture' of XP actu­ally. as soon as you have a cer­tain amount of read errors (and this amount is low, so it might be reached by just try­ing to rip one scratched DVD) XP auto­mat­i­cally switches the drive back to PIO mode and keeps it there…

  • Bill


    I am also hav­ing prob­lems enabling "DMA if Avail­able" I
    have tried every­thing sug­gested above, but even though the
    set­tings are for DMA if available…PIO is still showing.

    I have tried the fol­low­ing so far:

    1. Made sure "DMA if avail­able is displayed

    2. Tried switch­ing to "PIO Mode" and then chang­ing back.

    3. Finally I deleted the fol­low­ing from my registry;

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}\000x


    When I close down and re-boot, I then check my reg­istry
    again and they are BACK. For some rea­son they are get­ting re-installed on start Up?

    Any sug­ges­tions would be great­fully appreciated


  • snip­tools

    Bill – have you tried dis­abling the Sys­tem Restore fea­ture, then delet­ing those keys from the reg­istry, then reboot­ing, and then enabling the Sys­tem Restore back? Also, make sure you have deleted *all* instances of those keys; Win­dows tends to repeat the same keys in dif­fer­ent locations.

  • Bill

    Hi Shashank

    Thanks for your help. I tried what you sug­gested but on
    re-boot both of the fol­low­ing files are get­ting

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}\000x


    In my device man­ager under: IDE/ATA/Atari Con­trollers is
    ALSO the following:

    Intel® 82801DB Ultra ATA Controller

    Would this have any­thing to do with me not being able to
    delete the above two entries?

    Thanks Bill:)

  • jack

    hello, my prob­lem is that i finally got my sec­ondary ide to switch from PIO to DMA.
    how­ever, it is run­ning in multi-word DMA mode 2 instead of ULTRA DMA 5.
    ultra dma mode 5 is what it orig­i­nally ran at. i tried all the regedit and unin­stall dri­ver procedures.


  • Sieggs1

    Wow, this forum lit­er­ally saved my com­puter from the junk heap. Bought a new sec­ond drive for all my data. Spent 2 weeks try­ing to get it to for­mat and another 3 weeks try­ing to get both dri­ves out of PIO mode and into DMA mode. Tried every­thing in this forum. None of the sim­ple stuff worked, but then again, I knew it would never be that sim­ple. Turns out I had to remove an older ver­sion of Intel Appli­ca­tion Accel­er­a­tor to get Win­dows XP to even for­mat my drive. But I found out I had to rein­stall a newer ver­son of IAA to get Win­dows to read the dri­ves at DMA 5. Very strange. But some­one men­tioned it on this page so I tried it and viola! Now I can get back to my life. Although those 5 weeks of my life i will never get back.…

  • dr.dread

    Tried every­thing from this page — noth­ing helped with this PIO Mode issue.

    What worked out in my case was switch­ing onboard IDE con­troller from Enhanced to Com­pat­i­bil­ity IDE mode (BIOS setting).

    If it helps some­one, moth­er­board is ASUS P5AD2-E (Intel 925XE chipset) with AMI BIOS, Pio­neer 111d rw drive, Win­dows XP SP2. Now it's 5 min­utes to burn 4.7 Gb disc, before that it took 40+ minutes.

  • shit­face


    my dma prob­lem with my hard­disk is gone, using the solu­tion regkey deleting.

    thank you very much.

    sorry for my ter­ri­ble english :)

  • kai

    dear all,

    i've tried many things sug­gested here (delet­ing of all three Mas­terId­Dat­aCheck­sum found in regedit, unin­stall the IDE pri­mary where my dvd was in, make sure the 'DMA if avail­able' was set.), but still, failed and see­ing PIO :(

    my moth­er­board is giga­byte 965p DS4 with pio­neer DVR-111. win­dow XP ser­vice pack 2. The reading/writing speed is 1x, so i can't even watch a DVD on it!

    i'm using two SATA hard­disks. In BIOS, i set the SATA mode to AHCI, and onboard SATA/IDE Ctrl Mode to AHCI. I was won­der­ing, is this AHCI that cause the con­flicts? If so, if I change it to IDE, will that kill all data in my hard­disk right now?

    Please help!



  • ceko

    Thanks for all rec­c­om­men­da­tions, but my prob­lem was located on other place.
    Win2000 KTAPRO -> Jet­Way 880VIA MB
    The DVDROM and DVDRW was set to PIO by default.
    DVDROM was able to change to DMA with con­trol panel.…. set­ting, but DWDRW LiteOn dis­s­ap­peared from Win sys­tem after DMA change. All already men­tioned actions in forum didn't help.
    The last chance — fol­low old rec­c­om­men­da­tion: If all try­ing is witout suc­cess — read man­u­als care­fuly and for me was there!
    There was writ­ten : set NONE instead of AUTO for CD/DVD in IDE– BIOS settig.

    This short sen­tence brings me happy today even­ning WORKS!!!!
    How can be solu­tion sim­ple!
    Nice even­ning for all

  • Varun

    Thank you every­body at sniptools…I finally cleared the DMA trou­ble after weeks of search­ing the web…THANK YOU

  • Louie

    Thank you very much, It works & only takes a cou­ple of min­utes, well done to you.

  • vinesh

    when i open the nero for burn­ing the cd .its show­ing error mes­sage like that "dma is not acti­vated .you have to acti­vate your all dri­ves dma then try.please give the solutons

  • Dugi­modo

    Just to clar­ify, using older 40 way IDE cables will limit you to DMA mode 1 or 2, to get faster speeds you defi­nately need 80 way cables

    I didn't read all the posts so sorry if I'm repeat­ing some­one, but it seemed likely some of you had this problem

  • Dar­lene

    When I open the pri­mary IDE pri­mary chal­lel, the device type says auto detec­tion, the trans­fer mode is already set to dma if avail­able and the cur­rent trans­fer mode is set to dma mode 5 and i am able t i am unalbe to change device 1. the devict type is set to auto, trans­fer is set to dma if avail­able, but the cur­rent trans­fer mode says "not applic­a­ble".
    Now in the sec­ondary, device 0 is set to dma if avail­able but the cur­rent trans­fer mode is pio mode. For Device 1, it says the same as above's device 1.
    If any­one can help I'd greatly appre­ci­ate since I have no clue as to what I am doing.
    Thanks in advance:)

  • Mike


    This just made 6 hours of debug­ging until 1am com­pletely and totally worth while! My sys­tem is 100x faster now, and finally back to what it was like before!

    For any­one else look­ing for help, for me, my sys­tem slowed down after a loose SATA cable caused my drive to flip into PIO, and xp wouldn't let me switch it back!!!

    Best fix ever!!! You just saved me hav­ing to re-install xp!

  • MWFox

    Hi i've tried what you have sug­gested, but i'm unable to find the keys you have described on my registry.

    I have a old asus a7a266-e mb whit a amd athlon xp 1500 proces­sor and a max­tor 250gb/16mb buffer hdd as mas­ter whit a asus dvd as slave on pri­mary ide ch. + a max­tor 300gb/16mb buffer as slave whit a lg dvd-ram as mas­ter on 2nd ide ch., i've installed the ali dri­vers v.1.04 find on asus site, then dein­stalled it and replaced whit the v.1.091 dri­vers found on ali's web­site. Before i don't see on the ali ide mode util­ity the voice "auto" on, but when i've rein­stalled the dri­vers is acti­vated. What I had to do for nor rein­stall again windows?


  • White­fox

    Hi i've tried what you have sug­gested, but i'm unable to find the keys you have described on my registry.

    I have a old asus a7a266-e mb whit a amd athlon xp 1500 proces­sor and a max­tor 250gb/16mb buffer hdd as mas­ter whit a asus dvd as slave on pri­mary ide ch. + a max­tor 300gb/16mb buffer as slave whit a lg dvd-ram as mas­ter on 2nd ide ch., i've installed the ali dri­vers v.1.04 find on asus site, then dein­stalled it and replaced whit the v.1.091 dri­vers found on ali's web­site. Before i don't see on the ali ide mode util­ity the voice "auto" on, but when i've rein­stalled the dri­vers is acti­vated. What I had to do for nor rein­stall again windows?


  • Goldan

    Net2u — thanks for the jumpers swap-over trick. It did work out unlike the direct reg­istry manip­u­la­tion.
    — —  —  —  —  —  —  —  —  — -
    Giga­byte GA-965P-DS4

  • Lauh­dah­nan

    Remov­ing both ide con­trollers worked for me and I did not get a blue screen on boot up. But the cd-roms are in dma mode 1 they should be atleast mode 2 multi word. I have a 80 con­duc­tor cable for the cdroms, 40 con­duc­ter for the hard­drive which is in mode 2 mul­ti­word. not great but bet­ter than PIO mode. I will change the 40 pin cable and it should go up to mode 4 on this mobo. So in the end remov­ing ide con­tollers worked though might not be recomended. I was going to try mas­ter slave change but oh well.

  • atin zinga


    It is show­ing 3 Pri­mary IDE and 3 Sec­ondry IDE con­trollers on my sys­tem and one of my Pri­mary IDE switched from PIO to Multi Word DMA mode 2 in 0 and 1 devices, and one is run­ning in Ultra DMA in device 1
    ultra dma mode 5 is what it orig­i­nally ran at.

    The sta­tus of other Pri­mary and Sec­ondry con­trollers is that the DMA if avail­able mode is selected but no cur­rent mode is avail­able in either of the controllers.

    The DVD is also not play­ing in my drive.


  • Taeko

    The DMA enabling issue has been solved but now Nero shows tht the burn process has been com­pleted 'sucess­fully' but in real­ity the c.d hasnt been burned at all.……aaarrrgggghhhhhhhh

  • Rob J

    STARK you are a genius, sim­ple but effec­tive advice!

  • Bob

    I have a sim­i­lar prob­lem with the hard­disks.
    HD 0 (mas­ter) comes always in PIO mode but the HD 1 is OK in UDMA-5 mode.
    Would the registry-trick work? (Fujitsu Siemens Scaleo-P,2x 160GB HD,XP Home)

  • Bob

    The Prob­lem is solved. I changed the reg­istry an I could not beleive what hap­pened. For 1 year I had the prob­lems, could not lis­ten to radio on my PC with­out dis­turb­ing noise from f.e. viruss­can­ner, could not make good vide­o­record­ings. Now the prob­lem seems to be his­tory.

  • aong­has

    Hey thanks for the tip. I had trou­ble try­ing to enable DMA for my DVD writer but it's all good now. Cheers.

  • kickenchicken360

    ok soo.. i tried all of these tricks to try to set my dvd drive liteon shw 160p6s it was ultra dma mode 4 back in july in 06, now its ultra dma mode 2.. i tried switch­ing the ide cable with my hard drive which WAS ultra dma mode 5.. because of my stu­pid stunt my hdd now is also ultra dma mode 2.. i tried the reg hack where you delete the things. or where the reg add dword thing.. that says enalge ultra dma66 and that didnt work. i down­loaded the thing where it enables dma on the chan­nels.. didnt work. how can i fix this??? its caus­ing my com­puter to run slower than nor­mal. my drive now rips and burns slower than usual.. and my hdd access is slower and my com­puter feels.. bleh slug­gish.. help ??
    how can i make both drive ultra dma 5 for the hdd and ultra dma 4 for the dvd drive?

  • Gold­ly­Cat


    I am so glad I found this site, it looks VERY HELPFUL, How­ever noth­ing posted has worked for me.

    I down­loaded sonic DVD decoder on my new/not used Dell Dimen­sion 4700 com­puter which did not have a decoder originally.

    When I try to play a DVD the pic­ture seems a lit­tle slow and the audio is VERY choppy.

    I have tried a few things rec­om­mended in the above.

    I have tried delete­ing the Mas­ter IDDATACHECK SUM and the Slave in the Regedit, but in 000 there was only the Mas­ter and not the slave, I deleted the Mas­ter and slave, in 0001, they were both there, there is no 0002 there. There is no Mas­ter or Slave or in 0003 or 0004 when I reboot then check them, what I have deleted comes back.

    I have 2 pri­mary IDE chan­nels, I deleted them and rebooted, it did not change the PIO Mode to DMA.

    I have changed my DMA to PIO, then rebooted, then changed them back to DMA if avail­able, but it still is set to PIO mode in the cur­rent trans­fer mode.

    I have a Dell Dimen­sion 4700
    I have XP Home Edition

    This is what my IDA/ATA ATAPI con­trollers are set to:

    The first Pri­mary (there are two) is set to:

    Device 0
    Device Type — auto detec­tion (faded)
    Trans­fer Mode — DMA if avail­able
    Cur­rent Trans­fer Mode — Ultra DMA Mode 5

    Device 1
    Device Type — auto detec­tion (not faded)
    Trans­fer Mode — DMA If avail­able
    Cur­rent Trans­fer Mode — not applicable

    In my sec­ond Pri­mary, it is set to:

    Device 0
    Device Type — auto detec­tion (faded)
    Trans­fer Mode — DMA if avail­able
    Cur­rent Trans­fer Mode — Ultra DMA Mode 2

    Device 1
    Device Type — auto detec­tion (faded)
    Trans­fer Mode — DMA If avail­able
    Cur­rent Trans­fer Mode — PIO Mode

    If any­one can help me get my DVD's to work prop­erly, I would appre­ci­ate it soooo much


  • sally

    i have a qsi dvd sdr 081 cd rom and it reads dvds but when i put a
    cd in it acts like it want s to start but then says no cd in drive

  • joao from portugal

    hy i found this site and it look very cool.
    I have the same prob­lem that bill does.
    Shashank says that we should go desac­ti­vate the Sys­tem restore fea­ture. Where is that???

    Adeus e muito obri­gada (thanks and bye)
    Espero uma resposta urgente (please tell me as fast as posi­ble)
    Sorry for my eng­lish, i know it sucks

  • zahid

    thanks a lot dav­ester
    see ya in heaven dude

  • Finn

    I've tried most of the stuff on this page, but my 1st ide chan­nel HDDs stay as DMA2 and 2nd ide chan­nel HDD is PIO (DVD is DMA2 as it's sup­posed to be) I've tried delet­ing the SlaveI­d­Dat­aCheck­Sum and Mas­terId­Dat­aCheck­Sum , all over the reg­istry, but when­ever win­dows searches for plug and play devices, whether I press the but­ton in device man­ager or reboot, the keys pop right back there. Sys­tem restore is off.

    Win­dows XP SP2
    pri mast HDD DMA2
    pri slave HDD DMA2
    sec mast HDD PIO
    sec slave DVD DMA2

    Ideas on how to delete the keys?

  • wash­cloud

    all of u post­ing dma mode issues(…well…at least own­ers of OLD hardware),keep in mind that if some­thing does work for u,theres always the chance of the hard­ware not sup­port­ing it.…..;)

  • wash­cloud

    *..if soeme­thing does NOT work,even.…lol

  • Ahmed

    It works!!! Finally my anger is over and my lap­top DVD Writer is back on track, writ­ing full DVD in 20 min­utes, not 70 min­utes!! and also the com­puter is faster doing other tasks while burn­ing the DVD.

    Thanks guys! You are the best.



  • Kelvin

    I was in PIO and the sim­ple tog­gle to PIO then to DMA did not work for my drive. I then deleted MasterIDCheckSum(and slave) and rebooted. This did not work.

    Then I saw Post 99 by Simon C-S and I tried

    It WORKS:

    Updat­ing Dri­ver from Ultra ATA to Stan­dard Dual Chan­nel PCI IDE Controller

    1. My Com­puter -> Prop­er­ties -> Hard­ware -> Device Man­ager
    2. select device Ultra ATA(IDE Con­troller), chose it's
    Prop­er­ties -> Driver

    IDE con­trollers may be listed not only in 'IDE con­trollers'
    sec­tion, but in 'SCSI and RAID con­trollers' or 'Other devices'.

    3. Update Dri­ver -> Next
    4. ( ) .…
    (*) Install from a list or spe­cific loca­tion (Advanced)
    5. Next
    6. ( ) .…
    (*) Don't search. I will choose the dri­ver to install
    7. Next
    8. Click on Stan­dard Dual Chan­nel PCI IDE Con­troller
    9. Next
    10. Fin­ish
    11. Reboot

    Now my 2 hard­disks and CD-ROM are in DMA4 and 2 respectively.


  • Ahmed

    guys I noticed some­thing: the trans­fer mode is still (multi-word DMA mode 2) and there is no prob­lem but I checked today the regedit and the same key avail­able before in the same location(MasterIdDataChecksum).

    Is this nor­mal or it is a warn­ing that the prob­lem will hap­pen again?

  • Mar­tin

    This worked for me — I tried half a dozen other ideas before find­ing this one, thanks!

  • LNA


    Man…it does work..thanks a lot..
    Incred­i­ble that even after 3 year, this trick still help­ing people.


  • Xmike

    I tried chang­ing the reg­istry with­out any results. So I finally deleted my 6.1 nero and install my old ver­sion Nero OEM 3 that came with one of my per­vi­ous DVD burn­ers. Burns great now. I think they have CW block­ing on the lat­est versions.

  • deon

    I'm using winxp when i insert my flash drive onto my onboard usb port it gives me blue screen of death ever­time. What can i do to fix ?

  • deonkella

    I'm using winxp when i insert my flash drive into my onboard usb port it gives me blue screen of death. What can i do to fix the probem.

  • jaf­fa­muf­fin

    None of the above soft­ware tricks worked for me. I had to swap my 2 hard disks around from pri­mary to sec­ondary con­trollers and vice versa. Then it worked nicely.

    asrock Vsta quad, VIA chipset

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