That's the era as me (Windows 3.0 was released in 1990, 3.1 a couple of years later). I'm surprised your school let you have unfettered access to the DOS prompt - that would have gotten abused within minutes at our school. Even the BBC BASIC interpreter ended up getting removed from the network because people like myself would abuse the PC Speaker (which, to be honest, was the last the mischief I'd cause).

Frankly though, I preferred the actual BBC Micros and Amiga's that those IBMs were meant to replace.