Back up the Activation:
A strategy you can use to avoid the need to reactivate WinXP is to back up the product activation files and reinstall them when necessary. This may not always work but it's worth a try. First insert a diskette into the floppy drive (A:),next open the drive where WinXP is installed (usally the C: drive). Open up the Windows folders,then open the System32 folders. Scroll down to the (Wpa.dbl and Wpa.bak files) copy these files to the diskette.
Next time you need to reactivate WinXP:
Copy the (Wpa.dbl and Wpa.bak files)from the diskette to the C:WINDOWSsystem32 folders.