I am fixing my laptop, the hard drive works but is pretty much shit. Its a 20gb 4200 rpm stock HD for a compaq presario 1200 laptop. It recently began to go very slow, even after fresh reformat it still sucks ass. I want to get a new HD so i was wondering if I put a 40gb 5400 rpm in there, would that cause to much heat? Is there much speed difference between a 4200 and 5400? Any info is a ppreciated. thanks a lot, and happy holidays!