Embedded Web Page Video clips cause PC to crash

Hi everyone, hopefully someone knows the answer to this really annoying
problem I have, I own a Dell Dimension 9200, and people from Dell Have no
idea how to fix this, Ive even re-imaged my hard drive with no luck. What
happens is that when a video clip loads that is embedded in a web page, say
for example on the kids webiste www.nick.com, and you then click on the
spongebob link for example and the video loads on the page, it will then
start playing very briefly, kind of stall and some times stammer then the PC
shuts down and restarts automatically.......

Any ideas Guys and Gals.

Thanks....Nimzee