So, my hard drive failed. Got it replaced with a totally new one on warranty.
I popped it in, hooked it up and began a fresh install of XP Pro.
The install appears to have gone just fine... except when I got to restarting the computer.
When I start it everything seems normal until the moment the splash page disappears. At which point nothing happens. Just a black screen. No mouse icon. No BSOD. No pressing of any buttons (except for the power switch - which has the expected result of powering down) does anything.
I am guessing that this is a matter of me not installing the appropriate drivers for... well, probably a graphics card, but who knows what else. This is SO not my area of computer expertise.
Anyhow, drivers or not, I really don't know where to start. I did not get a disc of drivers from the store that sold me the comp, so I don't even have a simple answer to testing that theory.