Pc shutting off while gaming

[pesa69]

Hi all, while playing games my pc has been turning off randomly.
Specs are:
Intel Core i5 4670K
850W PSU Silverstone strider gold
16GB (2x8GB) DDR3
Gigabyte G1 Sniper Z87 Motherboard
Gigabyte 980 ti

It turns off prominently during CS:GO yet during Witcher 3 it took at least an hour. I ran a gpu test and everything was seemingly fine, but when i ran a CPU and memory test the pc turned off about an hour into the test. Im not certain of this but i suspect this started occuring after i installed Windows 10, i downgraded to windows 8 but the issue was still there.

 

My temps are:

On idle temps are:

GPU: 
Min- 34
Max- 41
Avg- 37

CPU:
Min- 21
Max- 35
Avg- 28

While in CSGO
GPU: 
Min- 34
Max- 58
Avg- 40 

CPU:
Min- 21
Max- 40
Avg- 33

While In Witcher 3:
GPU: 
Min- 34
Max- 63
Avg- 45.7

CPU:
Min- 21 
Max- 43 
Avg- 40

[HoiDaniel]

Your system might be instable. You should check if your problems occur when you run EVERYTHING on stock speeds.

[_JohnB330ci]

In Windows go to Event Viewer > Windows Logs > System, find any red exclamation marks and tell me what they are.

[Morgan MLGman]

If everything is at stock and you still experience sudden shutdowns, try to hook up some other PSU to your PC and check if the problem persists.

[_JohnB330ci]

You guys are presuming things way to quickly, he could simply just have a driver failure or conflict considering it started after he went to Windows 10. 

[manikyath]

tossing in this one again for good measure:

open cmd as administrator and type:

sfc /scannow

[pesa69]

In event viewer the two exclamation marks were: 

http://i.imgur.com/IoMw9k6.png

and

http://i.imgur.com/lu3TQAF.png

[computernerd123]

100% sure its a driver issue

[pesa69]

With "sfc  /scannow" it came up with "Windows Resource Protection did not find any integrity violations"

[Edgar R. Zakarian]

Try to update everything from GPU to Chipset drivers.

 

I'm thinking Windows 8 and 10 might use the same drivers.
Mine did anyway, it didn't install a specific Windows 10 driver for my GPU when I upgraded from Windows 7. (upgrading and downgrading might have this issue, clean install shouldn't)

Had to do that on my own, which fixed a lot of trouble.

-So try to do that specifically, and see if it helps.

 

- can you try another powersupply? From a friend maybe, just to rule out that idea. - Could be it is faulty? Experienced this before aswell.