well....they always recommend with XP that you do a fresh install when you swap boards. But this question has come up a few times lately...the guy in this thread
http://www.techimo.com/forum/showthr...threadid=92781 had his board die on him, he just threw another baord in and then it wouldnt boot at all..so he booted to the cd and did a "repair" installation and it seemed to work.
Personally I would do the fresh install just to avoid a lot of headaches with registry issues and conflicts and stuff.
But you could try first and see.....maybe some other people know some specifics as far as the best way to try it...like remove all the motherboard stuff from device manager first right before you shutdown to put the new board in etc.
(maybe back up any important data first, lol)....
JP