This might have happened to some of yall, where this screen comes up saying "the program has performed an illegal operation" and you're forced to stop doing what you were doing. What causes these? I mean, what is illegal that a computer can do?

well ...

Its mostly about memory. In a very simplified way, if a prog is using one bit of memory and another prog tries to use the same bit of memory (at the same time) then its considered illegal (goes against the rules made by the first prog, or windows as memory manager) and it blows up ....

One of a million examples, but you get the picture ...

A pain in the ass.

/I promise to stop spamming today.

Basically the program is trying to access something that its not allowed to to (like instructions that only the operating system is trying to use or accessing memory that belongs to some other program). Basically what Pab said, with the addition that it doesnt mean the cops will be at the door to arrest you any second...



The reason it annoyingly has to stop the program is that suddenly something the program expected to happen can't happen, so shutting it down is far better than letting it carry and get all confused, which would probably cause it to go a little insane and bad things would happen (especially if it was in the middle of writing stuff to the disk or something like that).