My computer has been suffering serious slow down of late; it takes ages to load up and log in, and every simple task seems to really tax it. I wouldn't mind much, but it's really affecting my media player. Everything I play sounds like it's been scratched to buggery, and it gets worse if I'm trying to do something at the same time, which is, y'know, kind of the point.

I've tried defragging, there's loads of memory left, and task manager's not picking up anything. The problems seem to have started since I tried to burn a mix (hi jp100!) on a CD it wouldn't accept, but I can't be sure. Theories?