We filled every conceivable space on those machines with pirated copies of gameboy emulators and various pokemon roms. It became a game of, will the computer admins ever realise, and if they do, will they do anything about it.
Long story short, they gave up trying to police it after about a year, when no matter what they tried, we always found another way to get the games back, in the process of course we learned quite a bit about computing (happy accident? Who cares, my love of computers started in that stupid class)
One of the things I remember about school computing in the 90s was how varied the equipment could be. My school had 2-3 computers per classroom, but 2nd grade had Apple IIs, 3rd grade had... possibly an Amiga?, and 4,5,6 grade had a mix of IBM PCs and one Mac, but with what ever OS originally shipped on them, ranging from straight DOS + Windows <3, win 3.1, and Win 95. It was wacky.