I am no expert when it comes of this stuff, but I had a similar problem on my old work PC where for no logical reason certain processes, or doing certain things like running a particular set of apps, or browsing to a particualr website that used java, and so and so on, I would get a blue screen and instant restart of the computer.

Problem - bad ram module.

Ram had to be replaced - fixed the problem. You could also try this program to test your ram modules http://www.memtest.org/