When you say "turn off", it's rather ambiguous, is it turning off like when you turn it off, ie shut down Windows, or is it as if the power is suddenly cut, does it restart/turn back on afterwards or do you have to do that manually.
The 5GB free space is something you must address but shouldn't be causing this. Try to keep 10%+ free space, more if it's a SSD.
Presuming your drivers, etc are up to date.
Anyway, the first thing that comes to mind with something like this is something overheating and the system shutting down/turning off to prevent damage. With certain settings Clear Sky can be a lot more demanding on hardware than SoC. You could try putting all settings to a minimum and see if it still causes the problem. (edit, but enable things like Vsync / frame limiting)
You could also test if your system is doing things like this due to either the CPU or GPU overheating, you could run a stress test for each while watching the temperatures to see if it causes the same problem, and if it passes then test on both at the same time. There may be a chance it's the PSU (power supply). Easy things to use for this is PRim95 to test the CPU and FurMark to test the GPU, you can get some info on them from a quick search or check [url=here]http://www.pcworld.com/article/2028882/keep-it-stable-stupid-how-to-stress-test-your-pc-hardware.html[/url]. You could use something like RealTemp to monitor the temperatures.
Also are you certain about your graphics card, I know of a Nvidia 540M, for laptops, the only Nvidia 540 for PC/desktops I know if is a Quadro and it can't be that.
Post edited August 01, 2015 by Grogger
