Nvidia driver crashs happen often, well, they do with me. Try updating your drivers after removing the old ones. But, a BSOD will not result in a flat out power down, never has, a restart, yes, but a total shut down, no.
Your only option is to pull the GPU and test in another machine, or pull the PSU and get a better brand name, as that brand is a crap brand. We can not diagnose further until you start trying with different parts, at this point, all we can do is flat out just guess, PSU, or GPU. My money is still on the PSU not providing enough power to the gpu, which WILL cause a driver failure as the gpu "fails".
BTW, the most obvious thing that points to a PSU failure, it this. (Though some motherboards with OVP will mimick this)
The issue is, during game, at no random timed interval, my computer will literally shut off instantaneously. Sometimes it will occur, other times I will be lucky enough for it to not happen. The key is, once everything shuts off at once, I try to turn on my computer with the power button to no avail. In order to actually start my computer back up, I have to unplug the power supply unit, hit the switch on it, wait until I hear this noise that sounds like the psu is actually totally off. Plug it in, switch it on, and then hit the power button.
A failing GPU wouldn't even cause that, unless the copper traces had somehow, magically shorted together.