try a new 80 wire ide cable on the hard drive
clean the dust out of the computer with a can of air paying paticular attention to the fans and h/sinks
redo the paste on the cpu with some arctic silver
http://www.arcticsilver.com/arctic_s...structions.htm
d/load and run the h/drive makers diognostic program on the hard drive
if it comes up clear
clear the disk with killdisk
http://www.download.com/3000-2092-10188745.html
then format it and reinstall
check your voltages in the bios