I ended up here.
All the fixes seem to revolve around Safe Mode, which I can't enter. I restart, hold F8 long before the Windows Logo comes up, and keep holding it down. All that happens is that the logon screen comes up. Nothing changes. No Safe Mode or any options appear. I'm now on a borrowed computer.
I don't have any sort of recovery discs or anything like it to hand. Attempting to use the fixes that are out there just runs into dead ends. I either don't have what they recommend using or what they tell me to do simply doesn't work (talking about Safe Mode).
Wiping it isn't much of an option. The computer came with Windows preinstalled, and I don't think there was any sort of disc or key in the first place.