Do you encounter a windows XP activation loop? Where it continually ask you to activate windows, but the activation wizard will tells you that it is already activated.
What you need: Untouched Windows XP Disc Installer or Original/Backup copy of windowsXP Disc
I always encounter this problem everytime I repair-install a Windows XP system. So here is what I did to fix the problem. First restart your PC then
1.) Log onto Windows using SAFEMODE with command prompt.
2.) Wait until the windows boot then Type "explorer" in the command prompt.
3.) Explore Windows XP CD and copy the TOOLS folder (located at support folder) to C:\
4.) In the TOOLS folder extract the DEPLOY.cab (this will create a new folder called deploy).
5.) Open the DEPLOY folder and run SYSPREP.
6.) Click FACTORY button. Notice that your PC will shut down.
7.) Power on your PC and wait till the windows desktop screen appear.
8.) Once finish Click RESEAL button and wait. Notice that your PC will shut down again.
9.) Power on again your PC and your done.
You may also be able to use the fix from Microsoft here