Sudden PC Shutdown Problems

[HowDoIComputer]

I'm having issues with my PC unexpectedly shutting down. This usually happens when I'm running a game, typically while in a loading screen. This only recently started and is really annoying as I think it corrupts my BIOS. I can't restart my PC unless I remove the battery from my motherboard and unplug everything for a while. Looking at temperature logs I haven't noticed anything strange.

I have no idea what could be causing the problem and I'm not sure where to start with testing. Could it be the PSU? GPU? How do I find out before buying replacements? I'm afraid of this issue damaging my computer and I'd appreciate any help you guys can offer.

My Specs:
Windows 8.1 Pro 64-bit
Intel Core i5 4690 @ 3.50GHz
8.00GB Dual-Channel DDR3 @ 934MHz
ASUSTeK COMPUTER INC. Z87-A
4095MB NVIDIA GeForce GTX 970
1863GB Seagate ST32000641AS
XFX XTR 750W

 

[Lutfij]

Are you sure your BIOS and device drivers are up to date? Have you uninstalled your GPU drivers using display driver uninstaller and reinstalling using the latest drivers off Nvidia's site? Regarding your ram, can you please state the make and model number? Are they both off a kit or are they mixed and matched to populate the slots for a cumulative capacity of 8GB?

Try a repair install and see if any progress is made. Last effort would be to recreate your bootable USB installer for Windows 8.1 and then reinstall your OS.