CPU Usage way too high

Sorry to start another thread today but I have a wierd question.

My computer usually uses less that 10% of the CPU when I’m just running a couple programs. Now it’s goin anywhere from 35% to 50% and all I have open is AIM, Kazaa, and IE… so is there anything that would all of a sudden just break my computer like that? I haven’t installed anything recently or anything. No clue what’s goin on, hoping one of you guys might.