citation:

"Changes to any one of the ten components or serial numbers that this file watches are logged. When three changes have been made the wpa.dbl file is deleted forcing the user to contact Microsoft to reactivate the software."

XP activation items
network card address
graphics card ID number
CPU serial number
SCSI host adapter number
IDE controller number
hard disk serial number
CPU type
Ram size
Volume ID
CD-Rom serial number

Before make changes on configuration backup the file wpa.dbl