XP Freezing, not booting up.

yeah, i am using the stock fan/heatsink. I've decided to get a Volcano 12 which should hopefully do the trick

maybe a late comment but im putting my info in here.

When I upgraded my mobo, processor, and gfx card etc, but kept the same HDD..I had lots of issues.

solution: formatted HDD, ran uber-fast ever since. Perhaps old Mobo drivers were conflicting, I don't know.

65-80 is amazingly hot, since Im running a P4 overclocked to 4.6ghz and thats running at 48C at the very time of typing this.

yup had the same problem.
I put my fan the wrong way in so every time the temperature went over 60 it freezed...
Took me a long time until I figured out the problem.
You might have your fan wrong too coz if you just have one working fan it still shouldn't be able to get over 80' ...