How to replace the motherboard on your XP (or Server 2003) computer without having to reinstall Windows

Want to upgrade your computer's motherboard, perhaps so you'll be able to add more RAM to your system than you currently can? Or maybe you have no choice - sometimes the momboard on a computer fails altogether, and you have to replace it. For Microsoft's tips on installing a new motherboard in a computer running Windows so that you won't have to completely reinstall the operating system and lose your settings:
http://support.microsoft.com/kb/824125/en-us