blackknight

to speed your pc up consider an investment in 2gig of ram 2x1gb sticks are very cheap these days, you will probably find the proccessor is working less after you install more memory.

as far as the noise next time you turn it on have the case open have a good listen to exactly where the noise comes from. i have had a few pc's at work where the hdd makes a "clunking" noise then windows magically became corrupt. needless to say hdd broke. if it is your hdd i suggest keeping your pc turned off until you get your hands on a spare and copy all your data over or even better "image" the disk.

hope that helps,