How to change product key in XP

1. Run regedit and go to:
HKey_Local_Machine\Software\Microsoft\WindowsNT\Current
Version\WPAEvents,in
the right pane double click on "oobetimer" and change at least one digit
of
this value. This will deactivate windows. Exit regedit.


2. Choose run from start menu and type in this command:
'%systemroot%\system32\oobe\msoobe.exe /a'
or
'oobe/msoobe /a'

to get the activation screen. Then You want to Activate by phone so
Click on
Activate by phone. Click Next.

3. In the new screen choose the option to change product key, and type in
the new product key (Corporate one only). You cannot use the FCKGW key.
Only
a new one that you have generated then....no need to click next

Click Update.

You now should reboot and be
done so just close that window, and reboot your system

4. Once rebooted check to make sure that your activated..


5. Enter the command in step 2 again for the second time to verify your
activation , you should see "Windows Is Already Activated".