Let me chime in here: You do not have to do a complete re-install of WindowsXP when you swap mobos (you DO have to for Win2K).
What you MUST do is boot from the WindowsXP CD and do a REPAIR install (2nd menu after the EULA, not the "Repair from Recovery Console" option in the first menu). This wipes the device manager, re-detects all devices and re-installs all generic drivers (you need to install the latest drivers yourself afterwards).
It also resets all Windows core files back to the versions on the CD (latest Service Pack and updates will need to be re-installed). You will not lose any apps or data.