From another thread:
AKDejaVu
Senior Member
Registered: Dec 1999
Location: Portland, OR, USA
Posts: 4962
Something that worked for someone else:
Install the new MB and Processor.
Boot from WinXP CD.
Select "Setup WinXP"
Select "Repair existing installation"
This should update the drivers so your new board will run. It would be a good idea to re-install SP1 after that.
AKDejaVu