Troubleshooting PC crash during video encode

[ontheteam]

I am having difficulty troubleshooting the following situation.

When my PC begins the actual video encoding process the system crashes; it simply shuts down. This occurs whether I am using virtualdub, avisynth, AutoGK, CloneDVD Mobile or NeroVision Express.
I have experienced the crash for all types of video encode: avi editing, ripping DVD to AVI, mpg to DVD. I simply cannot do anything on this PC. (I have successfully done all of the above on my laptop.)

I am confident it is a hardware problem, but I don't have the resources to simply swap out each component. Does anyone know what tests I can do to isolate the problem?

Hardware:
Motherboard - EPOX EP-8RDA3+PRO
Socket A CPU - AMD Sempron 2100 mHz
Memory - 2x 1GB Corsair Value Select PC3200 RAM

OS:
Windows XP SP2

[jagabo]

Probably overheating. Use a program like SpeedFan to watch the CPU temperature.

http://www.almico.com/speedfan.php