Unfortunately, replacing the motherboard with a different one from what came with that computer, then that will make your recovery discs useless. Pretty much, anything that would make your current installation of XP require reactivation, will also render the discs useless. Those factory recovery discs are made specifically for the stock configuration of your computer. About the only thing that you can change is the amount of RAM and the power supply, most anything else will make the recovery disc into a nice coaster. About the only way out of it now, is to purchase a fresh copy of Microsoft MCE 2005. The upside of it is that right now, it's fairly cheap, and will most likely come with a Vista upgrade, which makes it a pretty good deal actually.