Well, the XP re-installation was a relative success. We lost all of our bookmarks and settings, and we're going to have to re-install pretty much everything (which is going to be a major pain), but everything seems to be functioning normally.
The main problem's gonna be remembering where we put all of the driver and installation discs for everything so we can get back to full speed. Atleast we didn't lose all of the other contents of the hard drive (like all of our pictures and music).
I've got to send out some major props to my brother, for coming to our rescue with a shiny new copy of XP Pro!