Windows XP Can you enter a Genuine liscence / Serial number after an Installation of a non genuine liscence / Serial number

Posted on 2006-05-17
Last Modified: 2008-01-09
I would like to know if it is possible to enter a Windows XP Pro liscence / Serial number after you have installed it with a different liscence / Serial number.

Here is the senario:

A copy of Windows XP Pro was installed on one of our PC's the person used a copied CD and the serial number on the front disc. When i started to do the windows updates i noticed this one pc was giving us the "THIS IS NOT A GENUINE COPY OF WINDOWS" message. I know there are ways around this but i dont want a non geniune version of Windows on our computers.

I then purchased a full Licsenced copy of Windows XP Pro (the same version as the copy) and wish to Input the correct liscence / Serial number without having to scrub the computer and reinstall Windows again.

Is this Possible and How do you go about it  ?
Question by:ritchieuk
    LVL 13

    Expert Comment

    Here is how you change the key, but you may end up calling Microsoft when you activate it.
    LVL 57

    Expert Comment

    by:Pete Long
    LVL 57

    Accepted Solution

    bahy too slow

    or do this

    pen Notepad and paste these lines (only part under and above "********" ) :


    Windows Registry Editor Version 5.00

    [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\WPAEvents]


    Save the file as :  Part1.reg

    When you have saved the file as above suggested double-click it.WinXP will ask
    you if you want this entered in registry and on done will inform you that the thing was success.

    What this does?
    It deactivates Windows XP !!!
    After this the WXP are deactivated...for good !

    Go to : C:\WINDOWS\system32\oobe
    and run : C:\WINDOWS\system32\oobe\msoobe.exe /a

    Actually you can create a shortcut on desktop and enter these values in :

    Target : C:\WINDOWS\system32\oobe\msoobe.exe /a
    Start in : C:\WINDOWS\system32\oobe

    What this does?
    This runs the actual registration (activation)  program once again.
    On the screen:
    select option (telephone customer service) and click next at the bottom.

    On next screen select option
    "Change the product key"

    Enter your VALID (original) XP keys provided by Microsoft.
    Click "Update" and then click "X" on the upper right corner (close the window).

    Now we must activate the Windows once again.

    Run Notepad and write this inside the file :


    Windows Registry Editor Version 5.00

    [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\WPAEvents]


    save as:   Part2.reg

    Run this as the 1st file and everything is OK !
    WinXP activated for good !

    To check you can run msoobe.exe file shortcut to confirm that windows is again activated.
    You can easily skip it...

    Attention ! Restart windows and everything should work fine...

    if not (but it must), then ask Microsoft for another key.
    This is where the legal part ends !

    Expert Comment

    Yes there is.  You can download the utility here:

    If this doesn't do what you want vis a vis windows updates, post again.
    LVL 57

    Expert Comment

    by:Pete Long

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