One teacher in our school uses machines with MsDOS on them to run an old program to teach about electronics. its a good program, but the teacher really shouldn't be teaching, hes pretty much mental.

Anyways my brothers friend is really good with dos, he pretty much wrote a program that would start on start up that just said "play beep"
so he shut down the computer before he left, and then left for his next class. He later was called down to the room because he knew alot about Dos and was asked to fix the problem. so he fixes it, the teacher hails him as a hero, and some random person in the hour after him got in a lot of trouble.

My schools computers have really weak security, I could run through half of them and get my own admin acount without even trying, but I really feel no need.