Strange problem with Fujitsu Laptop

Alright, I have been all over the web looking for anyone with the same problem and I can't quite figure out wether its a software or hardware related problem. I have a laptop thats about 4 years old. It runs a Centrino 1.6 ghz processor and 1 gig ram.

It boots and runs fine. I can run all the heavy programs I want with no problems. Its quite stable. When I go to shut the computer down after running heavy loads it freezes at the "Windows is shutting down" Screen. It stays there and I have to pull the battery out to reset it. When I put the battery back in it will not boot for about 5 minutes or so. I can press the button but there is no response. Then all of a sudden it will boot after some time has passed. I am on windows xp pro.

I have completely disassembled and replaced the silicon on the processor. I have also tried switching out the ram. Can't figure for the life of me what could be causing it.

It doesn't have the problem unless it runs a heavy load. Boot down right after bootup is fine. Once its running for a while though, it wont boot down. Has anyone ever experienced this? Any thoughts? I would really appreciate any ideas. Thanks a lot.

-Grieves

 

you could try Dtemp, it's a small program that monitors your hard drive temperature. See if the temperature is much higher when it won't shut down.
It may not be the problem but worth a try.

 

I am not sure how hot a hard drive is supposed to be but it seems like it stops shutting down when it gets over 110 degrees ferenheit. The strange thing is, I can hear the hard drive spin down, and stop. But the fan and processor keep going, and the screen stays at "windows is shutting down." This laptop has no CPU temp, but it doesn't sound like any overheating problem I have heard of before. I am absolutely clueless. Maybe a new hard drive would fix it.