PC Freezing while gaming

[gamingyogi]

My PC seems to freeze while playing heavy games. It used to happen when I played Overwatch, but now it only happens in other (heavier) games, like Playerunknown's Battlegrounds and Far cry. I don't know why it stopped freezing when playing Overwatch but it might be because I turned the settings down. My pc parts are:
CPU: Intel i7 6700
GPU: Nvidia Geforce GTX 970 (msi)
Power Supply: Seasonic M12II Evo 520 Watt
RAM: 16 GB (8x2) Gskill DDR4
Motherboard: Gigabyte GA H170-D3HP
Storage: Samsung 650 120 GB SSD
Western Digital Blue 1TB HDD

The problem isn't that my GPU is overheating, since I have kept an eye on MSI Afterburner (nothing overclocked) while gaming, and the temperature never went above 70 - 75 when the PC froze.
I run Playerunknowns Battlegrounds on medium settings, and it runs perfectly untill it freezes my PC.

Can anyone help me with this issue?

 

[RARRAF]

Gigabyte GA H170-D3HP bios on the latest version.