Windows 7 - Processor Intensive Applications Crash PC

Everytime I run a processor intensive application (Video Compression, Running Market Simulations, etc.) After five to ten minutes my machine crashes.

If I run the same applications with shorter jobs it completes and the machine doesn't crash.

This is a hard crash where everything just blanks out.

I haven't made any hardware changes to the system and this issue is a new issue.

I ran all my avg anti-virus, ad-aware, and advanced system care and everything is running fine.

I am stumped.

What do you mean everything just blanks out?
It just shuts down? Freezes?

Power cuts out.

Welcome to SF, crashy

On the first view it looks to me like a Thermo problem. Any chance the machine overheats (due to dust build up in the heatsink and/or fan(s)?
Here are some applications that monitor your thermal diods:

Core Temp

Real Temp - CPU temperature monitoring

SpeedFan - Access temperature sensor in your computer

see what temps you get under load and get back to us

-DG

I think you may be right. I will try out the apps and report back. I will also try cleaning dust from the cpu area.

If it is a temp issue how can it be resolved? I have an Antec Sonata 2 case that has three fans. Do CPU's run hotter over time?

Absolutely...depending on the actual situation/is the pc on the floor or on a desk, are there pets like cats or bunnies around etc the dust build up can be too much in as little as 6 months
The more dust build up you have, the less effective is your cooling thus the cpu gets hotter and eventually shuts down (or worse gets destroyed in the process)
I usually just use canned air and a stiff paintbrush/old toothbrush to remove dust from the fan blades and the heatsink "griddle" but in extreme cases I take off the heatsink, clean it out, apply new thermal compound and be good to go for another 6-8 months

-DG

The working for short times but the crashing over longer periods is as good as a dead giveaway

Great. Thanks for the help!!

You might want to also clean the PSU fan aswell. If it gets to hot your PC can also shutdown. BTW what is the wattage of your PSU ? (it's not in your system spec)

Yeah, I agree. I've had an apparently similar problem with PC before. It seems that sometimes components automatically shutdown the computer when a certain temperature is reached without informing you of any errors. You should clean inside for dust, maintain air circulation, or if its a laptop try one of those fan bases or a lower power setting.

Just don't try to open the PSU...the capacitors in there hold a nice (un)healthy charge...they have warning labels for a reason