Windows – How to tell what Microsoft OS corresponds to a key

windows xp

I have an old computer whose hard drive is wiped. The Microsoft product key is on the back, but there is no reference to which OS it is. I know it must be some flavor of XP — is there any way to find out which one?

Best Answer

According to this article : Product IDs

Microsoft uses various Product IDs to identify variants of the Windows platform. A Windows product ID (currently, as of XP/2003/Vista) has the following format: xxxxx-yyy-zzzzzzz-zzzzz

The xxxxx section is the Microsoft Product Code, which in this case describes the platform, build, and version of Windows. Other product IDs with the same format, such as those found in Microsoft Office (and many other Microsoft products), serve the same purpose.

Here are some values for an English locale (the article also contains the Windows XP complete list) :

  • 55274 : XP Pro generic OEM
  • 55276 : XP Pro (upgrade)
  • 55276 : XP Home (?) †
  • 55277 : XP Home generic OEM
  • 55285 : XP Pro †
  • 55661 : XP Pro (retail)
  • 76475 : XP Home (upgrade) (?)
  • 76477 : XP Home Royalty OEM ‡
  • 76481 : XP Pro Dell OEM
  • 76487 : XP Media Center Edition 2005
  • 76487 : XP Pro Royalty OEM ‡
  • 76487 : XP Pro SP2 (retail)
  • 76487 : XP Pro SP3 (OEM)
  • 76487 : XP Pro volume license (with '640' channel ID)
  • 76500 : XP MCE 2005 (which is XP Pro with no domain capability)
  • 76588 : XP Pro x64 OEM

If the above doesn't help, the best source for definitive help is Microsoft Support.