I have several retail copies of Windows 7. Normally I make a note of which product key was used to activate which PC. Unfortunately, I slipped up.

I've just reinstalled Windows 7 on a PC, and I'd like to activate it. How do I audit my other PCs to find out which product key I used, so that I know which key to use for the reinstall?

The value in Computer Properties (that looks like 00123-012-1234567-12345) is not the one I'm referring to. This is the "Product ID".

I'm referring to the key that would normally be on the DVD case; the one that looks like AAAA1-B2222B-C3CCC-4DDDD-EEEE5. This, confusingly, is sometimes referred to as the "Product Key".

  • I'm not sure about Windows 7, but in XP, I think it's: right-click My Computer -> Properties -> General tab, somewhere in there. – FrustratedWithFormsDesigner Aug 3 '10 at 19:16
  • 4
    ???????????????? What r u talkin' 'bout? – r0ca Aug 3 '10 at 19:18
  • @Frustrated - I don't think you are referring to the same thing. – JNK Aug 3 '10 at 19:20
  • He was refering to the Product ID – r0ca Aug 3 '10 at 19:30
  • yeah probably. ignore my comment. ;) – FrustratedWithFormsDesigner Aug 3 '10 at 19:31

For Windows 7, 8, 10 you can use the slmgr command line program to reveal a portion of the key to help narrow it down.

  1. Open Start Menu, then type:


  2. Right click CMD application in the search listing

  3. Then click "Run as administrator"

  4. At the command prompt, type the following and press enter:

    slmgr -dli

  5. Wait for a little window to appear and then look at the value to the right of "Partial Product Key:"

    Windows Script Host Window containing partial product key

  6. Compare with and match to your windows product keys at hand. Note that this reveals the right most part of the ................-3V66T

  • Cool, that still works on the most recent Win10! Thank you for the detailed instructions! – j00hi Dec 29 '17 at 10:08
  • You sure it works? I've used another method to get my product key and it doesn't match with this partial product key. Adding, I'm also getting 3V66T as partial product key – i-- Aug 12 '20 at 12:46
  • Found this answers.microsoft.com/en-us/insider/forum/all/… – i-- Aug 12 '20 at 12:49

+1 on Magical Jelly Bean Keyfinder. I've used it many times to help friends recover their Windows product keys. Link


Windows Product Key Finder Pro is Freeware and works great. As it installs, be sure to uncheck the toolbars and updating program it offers.

Windows Product Key Finder Professional is a software utility which allows you to find and recover your CD Product key for Windows or Office programs for the purposes of reinstalling / repairing your Windows or Office setup. Recover your lost key or serial for Windows 7, Vista, XP, 2000, 2003, 2008. Office 2007, 2010, 2003, XP.


Directions here.

The jist is you need to get a 3rd party program, since it's in the registry but encrypted.

  • 3
    I've had good luck with the Magical Jellybean Keyfinder. Works like a charm. – Slartibartfast Aug 4 '10 at 2:21
  • MJK works great. – Shinrai Aug 10 '10 at 22:44

Not sure in win 7 but on XP's label where you find the Activation Key, there is the product id too. Slightly different but the end is the same and you can identify who is who this way.

  • Useful, but these are actually MSDN licenses (even though they're retail, rather than multi-activation or VL), so there's no label, unfortunately. – Roger Lipscombe Aug 4 '10 at 8:24

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