Did you just run windows update and install a new driver for something? I had the same problem, and techy brother in law figured it out...I've got a fairly quirky machine, as far as chipset and cards. The video card and most other stuff are Nvidia, so windows update assumed that my sound card was also Nvidia and downloaded the wrong driver. It wasn't, and caused a conflict that had the comp shutting itself down to protect itself.
no subject
no subject
So far, blue screen hasn't returned...so I'm keeping my fingers crossed.