Problems with games during lectures

Hello!

I work as a teacher at a highschool where every student has it own lap top as tool during lectures.

But we got a problem with some students that play games during the lectures, which of course is forbidden since it is disturbing the other students. But the students doesn't care some times. This kind of activity also take a lot of the bandwidth of the network.

So now is the question if any one can suggest a good technical solution to get rid of this behavior. If we cut of the admin-rights they just reinstall the OS at home.

So if any any has a technical solution to get rid of this please let me know.

Best regrads

Fredrik