I've seen a few of these recently. "Help me! How do I swap out a board and not have to reinstall Windows?"
So here's yer illustrated (Screenshots taken in WindowsXP) answer.
The first thing to do is ensure Windows is in a state where it can work on the new system. In the case of 2000 and XP, this just means that it has to be able to access the hard drives.
-http://episteme.arstechnica.com/eve/ubb.x?a=tpc&s=50009562&f=77909774&m=1400925745