Find Lost Product Keys for Microsoft Windows and Office

Two great tools that pro­vide the info in great detail.

UPDATED: You need your Win­dows XP or Microsoft Office prod­uct key, but you have lost them. Well no fear:

Down­load SIW by Gabriel Topala

[Rec­om­men­da­tion updated on Oct 2005, some com­ments below are deprecated.]

Just down­load it, run it, and it sees more than you will ever want to know about your system.

Older Rec­om­men­da­tions

Some neat util­i­ties to help you find stuff about your system:

Good thing about these tools is they also find a lot of other details about your system.

  • Dou­glas

    An excel­lent util­ity that finds lost win­dows and office prod­uct keys is at

  • Bar­dia

    I just fin­ished scour­ing through my regedit, and found excatly what you're talk­ing about.

    But FYI to any­one doing this on XP, it wasn't called prod­uct key for me, but it was called ProductId

  • Mon­goose

    Bar­dia, the Pro­duc­tKey is not the same as the 25 digit win­dows xp "id". The prod­ucts men­tioned on this page will give you a dif­fer­ent num­ber, check them out. Use­ful thread btw.

  • linda

    is ther any way to find win­dows 95 or win­dow s98 prod­uct key from a com­puter that wont load win­dows at all.i have sev­eral com­put­ers that i need to rein­stall win­dows 95 and 98 but i dont have any prod­uct keys for them

  • booga

    Win­dows 95 & 98 are quite easy:

    If your o/s is com­pletely toasted:

    Boot to DOS from a floppy or CD.
    Edit C:\WINDOWS\SYSTEM.DAT (might be hid­den / sys­tem, so if you can't see it then type "ATTRIB –RSH C:\WINDOWS\SYSTEM.DAT")

    Search for:
    Pro­duc­tKey (For Win­dows 98, this is the alphanu­meric one)
    Pro­duc­tID (For Win­dows 95)

    Win­dows 95 keys are also very easy to make up:


    a = date­code, ie 25297. you can put pretty much any­thing within rea­son here.
    b = plant num­ber — this needs to be a recog­nised value, ie 0018093
    c = batch num­ber — ie. 12345

  • David

    Using the regedit to find the prod­uct key code does not give the cor­rect num­ber. I used the link to and got the cor­rect infor­ma­tion for free. Thanks for the tip.

  • **Help**

    i have put in my win­dows 98 cd, and i am half way through the setup. Then, it asked me to enter in a win­dows prod­uct key num­ber, but i have lost my book­let. could some­one please give me the prod­uct key num­ber so i can install win­dows 98???

    Please please help me!

  • help!!!

    my friend installed the xp for his com­puter onto mine and we for­got to activi­ate win­dows in time. Now the trial period is over and we have no way of activi­at­ing win­dows because we dont have a prod­uct key and key find­ers can­not be used cos i cant get pass the activi­a­tion screen. is there another option apart from formating?

    des­per­ate for help

  • Matt

    I have win­dows xp but its locked me out and ive lost my acti­va­tion codes. any­way to try and get in to do what is sug­gested above???? thanks

  • Jeff

    I have to rein­stall Microsoft suite 2000 (mainly for microsoft word 2000) and i no longer have the 25 digit key code. Is there any way i can find it or get one????? Thanks.

  • ali­cia

    i have a copy of microsoft plus! for win­dows. and i do not have the prod­uct code. i dunno what hap­pened to it and i have refor­mated my comp so i cant get it off there. can any­one help me? i can­not even use microsoft cus­tomer ser­vice with­out the prod­uct key. if you can help me please email me at [email protected]. thankyou guys so much

  • / snip­tools

    This entry is not about MS plus. It's about Win­dows itself and Office XP. In gen­eral when you lose a code, the best idea is to con­tact either Microsoft or your ven­dor. Good luck.

  • / snip­tools

    Have updated the entry on Oct 17, 2005. The SIW util­ity by Gabriel Topala should show a lot of info about many appli­ca­tions. If MS Plus exposes this info through the reg­istry, you should see that too. Good luck!

  • ricky

    email me at my adress

  • fred

    i installed win­dows xp no prob­lem enter prod­uct key and every­thing
    went okay.I went to a friend and installed win­dow xp my ver­sion on his compyuter got to the point when it asked me to enter prod­uct key but it said invalid whats up

    thanks fred

  • anton

    thanks!!! i got my winXP prod­uct key with ease !!!

  • anton

    one more thing would it be pos­si­ble to get from any­one a prod­uct key of win­dows ME. it was purchsed legally how­ever a cousin of mine lost the key and he could not install the prod­uct at all. how can we retrieve the key for installation???

  • Teresa

    I had to buy a new hard drive and I installed win­dows 98 but I lost my prod­uct code. I have the win­dows xp home upgrade but it will not run until the 98 is in and I need a prod­uct code. Is there any­thing I can do?

  • linda

    i just got the home edi­tion of xp in sep­tem­ber /05 my other com­puter had a games video card on it,it was win­dows me,then it crashed i had another per­son look at it and he installed the win­dows 98 on it so it still crashed, now i have a new mahjongg egames that i got for christmas,and it went ok for 1/2 hour then it crashed it said i needed a video card and some dri­vers to play this game, i am won­der­ing how to look for the dri­vers also if this game is not installed prop­erly ,or whether it will not be able to play on my machine because i noticed it goes only up to 2003 in years, out dates for 3 years and i didnt get to be able to play it again,i thought if i delete the game and rein­stall it it would work but no way how do i find out what i can do to get it up and run­ning again, or should i go and get my money back before the 30 days are up

  • Ron

    HI, I need seri­ous help, My key code acti­va­tion for my xp home sp2 ver­sion won't work, i had to ear­lier fomat my hard drive and tried to re-install and now microsoft says i have to buy a new pro­gram to get key code to acti­vate win­dows again. I already have the pro­gram and a key code, but told some­thing wrong with it and need to re-enter new key code #. Now my win­dows won't let me log in until I enter and reg­is­ter a new key code because the 30 days elasped as of today, so can some­body help me with a new key code. PLZZZ or tell me how to unlock that win­dow to get to my desk­top. Thank you very much

  • zdw

    I am try­ing to rein­stall microsoft works suite 2000 on my com­puter and it is ask­ing for a 25 num­ber cd key for the word pro­gram. My cer­tifi­cate of authen­tic­ity has a prod­uct id num­ber on it, but that does not seem to work for the 25 num­ber they are requesting…what should I use?

  • bean­bag­dan

    My gen­uine prod­uct key for Media Cen­ter 2005 wont work with soft­ware loaded from another disk, and the retailer I got it from wont replace the dam­aged disk.

    How do I get past the Prod­uct Key page if it wont accept the code? (MS just keep telling me to go back to the retailer who is non-helpful)

    PS I have a crack disc but how will that work with­out get­ting the OS happening?



  • kelly

    i have lost the prod­uct key for micrisoft word what should i do?

  • Carla

    Is there a way to get the prod­uct key straight off the CD when the key has been lost? I have a lap top with an older ver­sion of XP and the oper­at­ing sys­tem sud­denly said " there wasn't any". So I can't retrieve the key through the pro­gram. I was going to put it on my other com­puter and do it, but it would unin­stall it, and this one was down­loaded off the net.

    Any step by step sug­ges­tions? That ver­sion of XP has been a royal pain in the butt. Would it be bet­ter just to copy the ver­sion from this com­puter over to the lap­top, and if so how would I do so effectively?

  • Tejas

    I have a full microsoft plus! media cen­ter but i dont have its acti­va­tion key, please help me if any one have it. Thanks!!!!!!!!

  • Sky­lar

    hi, i have microsoft word on my com­puter, but i dont have the prod­uct key. i am beg­ging you, if any­one has it can you please e-mail it to me PLEASE thank you

  • Hira

    I install Microsoft office 2000 pro­fes­sional, but i lost my CD label.Now I want prod­uct key for this software.Please HELP ME!