XP and 2000 are great to automatically detect devices and new hardware.
*** However *** If you change a major part out such as the motherboard, the computer may possibly boot up and find everything it needs, however it will not run properly because of previous settings resident in the programming.
The only way of fixing this is saving your favorites, documents, mail folders, etc. (important files) to floppy or cd. Then wipe the machine out and do a fresh install.
*** After the install, do not forget to goto the motherboard's manufacturer website and download the latest drivers... (It is best to do this first and save them onto a cd so you have them locally)
Good Luck.