Itronix

Hello. My sister gave me a Dell Latitude CPx j650GT. It was slow, so I cleaned it up and I am purchasing two 256mb modules for it to speed it up. I didn't think much about it, besides of it being an irritating noise. The harddrive makes noise. It isn't screaching, thumping, or really grinding. It is just noisy. It sounds like a normal harddrive, if you were to put your ear up to it, but amplified. I ran disk check, and it didn't find anything. It has a twenty gig drive.
It is fairly slow (very slow loading XP), probably because it isn't up to specs for XP, so I bought ram. Besides that, it works great. So, with your opinions, is the harddrive failing? I am curious, because I don't want to lose XP.