Debugging :: BSOD After About Half An Hour Of Playing Games

I'm having major issues with my GPU while playing games on my MSI GT60 0ND. I've tried several different drivers, from the one that came with the computer when I bought it, the one I could download from MSI's own webpage, to the newest from Nvidia. I was wondering whether you could see something in the dump files that could indicate the source of the problem.

The problem started about a year after the buy (which coincidentally was when the warranty ran out). It started out with a few BSOD's from time to time (video_tdr_failure - nvlddmkm.sys), and has now progressed to the point where the computer will BSOD shortly after playing. The problem started after I upgraded to Windows 8.1, but still persists now that I've downgraded back to 8, although it seemed like the problem was gone for a few days. The last BSOD happened while playing Hearthstone, after about half an hour of playing (which is longer than it usually takes).

Is this a software-related problem, or is the GPU simply shot?

Computer specs :
Computer: MSI GT60
CPU: Intel Core i7-3630QM
Graphics Card: Nvidia GeForce GTX 675M / 2GB GDDR5
Ram: DDRIII 12GB (4GB * 3)
HDD: 750GB 7200RPM