I have been getting this problem for months now, and it's driving me insane. I flashed bios, updated it, updated processor drivers, ran full diagnosis on everything, memory stress test, short video tests, updated GPU drivers (both intel HD4K and GT630m), set to high performance battery mode, disabled PCI express, everything but it just refuses to work. I also tried rolling back drivers to dell's one. same result. I upgraded to windows 8.1 Pro if that's relevant.
When the GPU crashes, the screen goes black and brings me back to desktop with a error message: "nvlddmkm stopped working" or "Nvidia kernel mode driver stopped working and has succesfully recovered" or in some occasions the gpu can't recover properly and the whole system crashes with a sound loop (buzz noise). I've set TdrDelay to 8 seconds, tried disabling it, nothing stops the crashes. My GPU /CAN/ run graphics intensive games but even for the lowest of graphics it still crashes. I have no single idea what could be the problem.
I also get lots of LiveKernelEvents 141. Probably related to the video card but I don't know what it could possibly mean. I also downloaded every important update in Windows Update.
Help is welcome and thanked.