3-4 hour 100% CPU usage leads to crash.

Hello there, I was linked to this site via looking for a solution to this problem, despite being unknown, I hope you can help me!

About 2 months ago, my computer blackscreens -> reboot/windows.

It is not a virus, I have concluded that.

I installed EVGA Precision to monitor Graphics card temp, and it crashes even with it hovering around 49-54C.

I brought it into the place I bought it, and they said they cleaned out the heatsink, and checked the temp of all running components and said everything seemed fine, the same day I get home and run a virus scan + 2 hours of video compiling (sony vegas), it crashes.

I can leave it idle forever and it will not crash, its only after I use any program which uses up a lot of my CPU power.

From what I have read on this website, I have come down to it either;

A) Something I installed that changed my bios settings that either increased overclock, or lowered the temp at which my computer shuts down to save itself.

B) My power supply cannot maintain high amounts of draw for long periods of time (burnt out?)

Am I right in these assumptions?

Any help is much appreciated, I have been trying to fix this for about 3 weeks now that I cant take it rebooting anymore =(

PS: I also bought 2 new ram 2 gig sticks a week ago thinking maybe the ram had burnt out from being too hot, but that isnt the problem.

well the first assumption i made is that your not stable and your cpu isn't getting as much juice as it should. how are your cpu temps looking? what cpu, and are you using stock heatsink? what voltage is your cpu running at? again im assuming you know how to retrieve this information

also, how long have you had this machine for?

If a cpu overheats, it will normally throttle itself, slowing things down, but not crashing.

Are you overclocking? If so, reset to default speeds.

1) On the off chance that it is a ram problem, run memtest86+ for a pass or two. It should show NO errors.
2) To take the vga card out of the equation, run prime95 with rounding error checking specified. Monitor your temperatures. Speedfan should work. Run it long enough to get to a sustained maximum temperature. There should be NO errors.

Is your OS legitimate and up to date?

Is there a more current bios update to your motherboard that might address the problem?

You say 100% CPU usage.... but not *what Process* is using all that power. Please identify the source of the usage, and you'll have gone a long way towards solving the issue. If you need a tool to do that:

Process Monitor (Task Manager on steroids)
http://technet.microsoft.com/en-us [...] 96653.aspx


Other things you can do:

How to generate a system health report:
http://www.vistax64.com/tutorials/ [...] eport.html

checking the Reliability Monitor for errors:
http://www.vistax64.com/tutorials/ [...] nitor.html

Troubleshooting Sequence:
http://www.vistax64.com/tutorials/ [...] uence.html


How to check system files in Vista:
http://www.vistax64.com/tutorials/ [...] mmand.html

How to perform a Startup repair:
http://www.vistax64.com/tutorials/ [...] epair.html

How to perform a full system repair:
http://www.vistax64.com/tutorials/ [...] vista.html

Suggestions to Improve Performance
http://www.vistax64.com/tutorials/ [...] vista.html