I can't seem to think of any other reason except for a faulty driver. I'm sorry if I missed it, but what video card are you running?

Try this:
http://www.opentechsupport.net/forum...ic/2789-1.html

You MAY be suffering from the The Unhandled Exception c0000005 error, but it is kinda old.

Also, check the integrity of your memory. One bad stick can be causing your problems, and Dell is quite notorious in slipping in "refurbished" modules in there.

As a last resort, try flashing your BIOS, and if that doesn't work, your computer is definetely overheating. Give a power supply a try.

Good luck