Display Properties

Is there an easy way to set the display properties back to the default settings? A friend of my thought it would look cool if he setup is computer in basic black trouble is everything is black. The backround is black, the text is black. Everything is black and more black. (except some of the icons) I cann't change it back because everything is so black I cann't read anything to make the changes!

Can I go to the registry and change it all back to the default setting? And if I can what changes should I make?

Any and all help would be much appreciated!

Have you tried safe mode?

Yes I have. I've tried to make the changes there but it doesn't fix the problem.
Also he has four User Accounts setup on his computer (for the rest of the family) but it's only his thats affected and it's setup as administrator.