I yielded to temptation and tried a windows XP disk that came with another computer to see if maybe I could repair the installation. Didn't work. Somehow I got sucked into trying to reinstall windows. It went partway through the installation process and AFTER it reformatted the hard drive it asked for the key code! You'd think that they'd do that first, but NoooOOOOOooooo.
Anyway now I have a computer with no OS, and a bunch of installation files chilling on the hard drive. I might get me a copy of Linux and burn it to a CD and give it a whirl. Gotta wait for some free time though.

Or maybe I'll just strip out the usable components for spares.