How to change XP Serial/License number

Go to / Start Menu/ Run/ Type regedit and click OK.

Before any operation in the registry, he should make a backup of the registry as a precaution

• In the Registry Editor, click File then Export and save the registry at a place where you can find the file.
• Expand the options until you get the key:

  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\windowsNT\CurrentVersion\WPAEevents

• Then on the right panel, change the value OOBETimer by changing the number.
• Close the registry.
• Start Menu> Run> Type:

  %systemroot%\system32\oobe\msoobe /a

• Choose Activate Windows by phone, then click Change Windows key and then enter your new key and click Update.