HOW TO: Change the Volume Licensing Product Key on a Windows XP SP1- Based Computer

This article describes how to change the Windows XP product key in a Volume
Licensing installation.
Because of changes in Windows XP Service Pack 1 (SP1), Windows XP-based
computers that use a leaked product key that is known to be available to the general
public may not be able to install SP1 or automatically obtain updates from the
Windows Update Web site.
There are two methods that you can use to change the product key with volume
licensing media after installation. You can use either the Windows Activation Wizard
graphical user interface (GUI) or a Windows Management Instrumentation (WMI)
script.
The easier method to use is the Use the Activation Wizard method. Use this method
when you only have a few computers on which to change the product key. The Use a
Script method is best when you have a number of computers on which you have to
change the product key.