When you restore Windows XP to a new disk drive, you receive the following message when you restart your computer:

A problem is preventing windows from accurately checking the license for this computer. ERROR 0x80090006.

This problem is the result of the hardware ID on the restored installation being different from the hardware hash calculated for the current hardware.

To resolve this problem, perform an in-place upgrade of Windows XP and reactivate the Windows XP license:

How do I perform an in-place upgrade (re-installation) of Windows XP?

Windows XP frequently asked questions about Windows Product Activation (WPA).