Recovering a Windows XP License key - Super User

Recovering a Windows XP License key

2009-08-30T12:37:30Z

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.

Answer by nik for Recovering a Windows XP License key

2009-08-30T12:41:00Z

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).

Answer by Kez for Recovering a Windows XP License key

2009-08-30T13:13:06Z

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.

Answer by Molly7244 for Recovering a Windows XP License key

2009-08-30T13:25:51Z

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.

Answer by hyperslug for Recovering a Windows XP License key

2009-08-30T21:45:34Z

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

C:\WINDOWS\system32\config\software

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:

KHCQQ-BBCW2-TT7QR-F42M6-V3YQY

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

Answer by palswim for Recovering a Windows XP License key

2021-09-16T19:49:02Z

If you are able to extract the 15 bytes from positions 0x34 and 0x52 (52-66) in the DigitalProductId Registry Value as a Hex string, you can use the following Python (Python 3) script to convert the bytes to a Product Key:

import sys

def eprint(s, *args, **kwargs):
    sys.stderr.write(s.format(*args, **kwargs) + '\n')

class KeyConv(object):
    _alphabet = 'BCDFGHJKMPQRTVWXY2346789'
    def __init__(self, val, verbose = False):
        self._val = val
        self._verbose = verbose

    @classmethod
    def _int_to_indices(cls, val):
        while (val > 0):
            yield (val % len(cls._alphabet))
            val = val // len(cls._alphabet)

    @property
    def key(self):
        a_idx = list(self._int_to_indices(self._val))
        s_key = ''
        for i in range(0, (25 - len(a_idx))):
            s_key = s_key + self._alphabet[0]
        for idx in reversed(a_idx):
            s_key = s_key + self._alphabet[idx]

        if len(s_key) != 25:
            if self._verbose:
                eprint('Invalid Product Key length: {} ({}) from 0x{:X}'.format(len(s_key), s_key, self._val))
            s_key = s_key[-25:]
        chunks_key = (s_key[(5 * pos):((5 * pos) + 5)] for pos in range(0, 5))
        return '-'.join(chunks_key)
    @classmethod
    def from_hex_string(cls, shex, *args, **kwargs):
        return cls(int(shex, 16), *args, **kwargs)

if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser(description="""Decode a Windows Registry value to the corresponding Product Key""")
    parser.add_argument(dest='hexstring', help="""The hex string to decode (from the Registry)""", metavar='STRING')
    parser.add_argument('-v', '--verbose', dest='verbose', action='store_true', help="""Output more information about conversion""")
    args = parser.parse_args()
    k = KeyConv.from_hex_string(''.join(args.hexstring.split()).replace(',', '').replace('\\', ''), args.verbose)
    print(k.key)

Sample run:

> python3 key-conv.py -v "A2 23 51 D0 2A 38 5D 22 C4 41 6B 87 43 C1 00"
Invalid Product Key length: 27 (CDKHCQQBBCW2TT7QRF42M6V3YQY) from 0xA22351D02A385D22C4416B8743C100
KHCQQ-BBCW2-TT7QR-F42M6-V3YQY

You can see the details about where to find the DigitalProductId Value in another answer, but essentially, look in the Registry Key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

If you cannot access an interface to the machine, but can access the filesystem, find the Registry Hive at:

%WinDir%\system32\config\software

If you are having trouble extracting the data, you can Export the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion Key and then open the resulting .reg file. If I wanted to expand the script, I could add a Registry or .reg file extraction routine.