to re-install XP without tears
1. Copy the file c:\windows\system32\wpa.dbl to a floppy.
2. Reinstall Windows XP.
3. Boot to a DOS disk if you are using FAT, or to the Recovery Console if using NTFS.
4. Copy the file from the first step above back to c:\windows\system32.
5. That's it - because all of your hardware is the same as before, your copy of WinXP is still valid according to the previous activation.
So Chegs when you have finally re-activated XP do the above and it's easy to re-install anytime!