sounds like it starts up with your computer, lags along, trying to run, then dies out. same thing happened to mine at one point. man, did it get noisy!

well, y'know something? those fans aren't made to last forever. the additional problem of dust and webs getting in there makes them last for fewer years. it's nothing you've done, it just happens. they do need to be replaced eventually. you'll find someone to help you if you don't do it yourself. ~hugs!~