Update on the situation: The bios chip, and therefore the motherboard, is indeed stuffed. I took it around to the local guru who installed a new mboard but he also reinstalled a copy of XP Home over the existing copy of XP Pro!
Basically, it goes once again, but all the drivers need to be downloaded and installed again. Most of the data that was on the hard drive is still present except for the stuff that was in two password protected user accounts. One of them mine, the other was my sister's. The accounts show up in the documents and settings folder but can't be opened. The non-password accounts all seem to be fine.
My question: Is the data lost forever? If not, how in blazes do i get the stuff back?
You here, Hive? I could really use your brains on this one.