I threw out a Windows XP machine a while ago (the motherboard failed). I kept the hard drive and the XP installation media.

Problem is the license key was on a sticker on the machine - doh! The original manufacturer has gone bust (Evesham) and I suspect that Microsoft will be of little help.

Is there any easy way to get the license key off the hard disk? Can I just find the file with the registry data in it and get the key using a hex editor?

I really need a spare XP key for use in a Windows VM.

  • Keep in mind that most OEM XP and up license key stickers were special numbers to begin with. You can't usually reinstall with that number, and I believe the number in the registry reflects the number on the case. – Paul McMillan Aug 30 '09 at 15:06
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    Note that Fortyrunner has said that the registry is on ANOTHER disk from another computer. Using Jellybean/WinKeyFinder/KeyFinder as suggested will not work in this instance. – Kez Aug 30 '09 at 17:19
  • and why would winkeyfinder not work? connect the HDD to any computer (to be sure, remove all other HDDs), now boot from a windows XP CDROM and run a repair installation, then retrieve your license keys with winkeyfinder. walk in the park. – Molly7244 Aug 30 '09 at 21:02

If the old machine had a sticker, it was most likely an OEM license.

OEM licenses cannot legally be moved from one computer to another one. They die when the computer dies.

But, in answer to your question...

Load the old registry hive on your new computer and then find the XP key. -- EDIT make sure that you open the SOFTWARE hive instead of SYSTEM mentioned in the first guide, then open this just-opened-offline hive in the second guide.

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    After further reading, if you have never reinstalled XP with the key on the sticker - you are unlikely to retrieve it by any means. OEM's usually use a generic key (not the one on the sticker) so that is the one that you would get from the registry. – Kez Aug 30 '09 at 17:21

WinKeyFinder - · View Windows XP CD Key · Change Windows XP CD Key · View Windows Vista 32bit Edition CD Key · View MS Office 2007 CD Key · View/Change XP Key · View/Change MS office Key · View Win98 Key · view Win2000 Key · View .Net Key · View Windows2003 Key

Magic Jelly Bean Keyfinder works on Windows 95, 98, ME, 2000, XP, Vista, Server 2003, Server 2008, Office XP, Office 2003, and Office 2007 family of products.

and while you're at it, backup your XP activation files, AFAIK the latest WinKeyFinder features this option, if not, here'a a tutorial.

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Apparently Nirsoft's ProduKey can do this:

produkey.exe /windir [Windows Directory]

Load product key information from another operating system on the same computer. The [Windows Directory] specifies the base folder of Windows installation, for example: c:\windows, c:\winnt This feature is only supported on Windows 2000/XP/2003/2008/Vista/7.

If that doesn't work, you'll have to dig it out of the registry file manually by searching

for the registry key

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\DigitalProductId

using a hex editor I think.

Bytes 52-66 (0x34 - 0x42) of this key hold a 15 byte number.

In Hex, it's a 30 digit number: A2 23 51 D0 2A 38 5D 22 C4 41 6B 87 43 C1 00

In Binary, a 120 digit number: 10100010 00100011 ... 11000001 00000000

Converted to base 24: 751AA001EHCCLAB3JH8KDIGAG

Mapped to Microsoft's custom base24 alphabet "BCDFGHJKMPQRTVWXY2346789" and a hyphen every 5 chars:


I did it this way about 4 years ago, so I'm really hoping ProduKey works.

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This article might be useful: Find the Windows XP Product Key Code.
There is also this another link on a ViewKeyXP tool: Retrieve your XP Product Key.
(that second link has some other tool references too).

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