hehe, reminds me of when my friends come over to my house and see my desktop. they always ask 'is that Windows?' or 'is that Linux?' tehl3x's idea is good, that way you don't have to be there to explain to your friends everytime they want to do something. on the other hand, if you run out of time, you can always switch back to Explorer.
Just shut off your computer. You don't want people messing with it anyways., especially poeple who think they know alot about computers and end up fucking it up anyways.
If they can't figure out how to use it, they shouldn't be touching it in the first place. It's like natural selection, the smart ones will figure out how to use it, and the chances of them fucking it up are slim. The one's that can't figure out how to work it, would only blow it up. It's god's way of filtering out the idiots, I say keep it as is, let them figure it out.