This article was previously published under Q305356
After you restore a previously-activated Windows XP-based installation from a backup, you may be prompted to re-activate the installation.
This behavior can occur if there are significant differences between the current hardware and the hardware that was in use when the original installation was backed up. These hardware changes require product re-activation because the installation now appears to have been installed on a new (additional) computer. Windows XP may prompt you to re-activate the computer under any of the following conditions:
You restore from a backup of a non-activated computer.
You have changed or added hardware, and this has caused Windows XP to become out of tolerance.
You restore from the last backup that was made before the hardware changes and prior to activation.
To work around this behavior, use any of the following methods.
Create another backup after any successful hardware changes or installations occur. In addition, you should create the backup after you re-activate the computer.
NOTE: This can be an incremental backup rather then a full backup, because an incremental backup is the minimum that is required to ensure that the Windows Product Activation database files (Wpa.dbl and Wpa.bak) are backed up.
Be prepared to re-activate the computer after you restore a backup set that was made prior to hardware changes.