This problem has existed since NT4 and carried over to 2000 and XP, before you replace the motherboard you should remove all the motherboard drivers from the system (Right click MyComputer, go to properties, Hardware, Device Manager) then remove all motherboard related devices (hdd controllers, etc) this should be done from same mode. Then put in your new board and you should get to windows fine, it will find a lot of new stuff but you can get it to run. One problem with this is a lot of residual stuff in the registry that has the potential to be problematic, so a fresh load of the OS is preferable (although it should be fun calling Microsoft to see if they will let you use XP since it's already been activated once). Also, is this a question for the phpbuilder's site?