Ok, so making an image of the hard drive might be an idea before playing with that.
Windows doesn't encrypt anything in the User folders by default does it?
It's funny that this cropped up, because that's exactly what I was doing at work at the time.
I was also trying to stop students from setting a password on their account on our crap netbooks. Do you think you can stop it in XP Home? No you sodding can't.
I'm resorting to bunging Pro on them instead :'-(