Photoshop :: What's Causing CS6 To Shutdown Program And Computer

CS6 not only shuts down itself, it shuts down my computer. I have a high-end graphics card (which I specifically got to run my photo-editing monitor), i7 processor, Win8, 64-bit, high resolution. It always happens, without fail, when I choose a large size brush or whatever tool in cloning, spot-healing, dodging, burning, etc). Otherwise, it runs fine. But if I choose a large brush, etc, it only shows me a half circle instead of the full circle, freezes PS, shuts down my computer, and then the computer re-starts.

I used this same PS program on my previous Win7 64-bit computer, which had far less capability, processor, graphics, and other credentials than this current one. It has nothing to do with having other apps running because it happens regardless. It has nothing to do with Bridge because I don't use Bridge. It happens every time as described above. When the computer boots itself back up, there's an option for me to send the notice of the error to Microsoft, which I've done about 50 times. Could it have something to do with Win8? Hope not, because I checked before I (regrettably) got a computer with Win8 to make sure Photoshop was compatible with Win8.