In the end, I booted it up with the Linux System Rescue CD, and discovered that the hard disk had failed!
So I purchased a new disk from Dabs (Seagate 160GB SATA) and I'm reinstalling Windows. The particular disk I got needed a SATA driver from a floppy, so I downloaded that (motherboard: ABit V17). However, after formatting with NTFS on the current partition (not a new one), it prompted me to insert a VIA RAID Combo Driver. Why is this? I'm not going to use RAID!