The fact that I haven't had more than a couple minor issues, after changing boards and cpu, is that the exception to the rule? Or do the bulk of the problems creep up slowly, one by one?
I just changed my motherboard and CPU (D975XBX2 and Core 2 Duo E6600) but didnt reinstall or repair windows xp. I turned on the machine and besides having to reinstall a few drivers, it works fine. Maybe I will run into issues with Windows XP but as of yet, everything seems ok.