Pc randomly reboots when playing games

When I play games like assassins creed origins or VR games my pc randomly reboots.

My pc specs are, motherboard: gigabyte G1.Sniper B6 CPU: Intel Core i5-4460 video card: Gigabyte GeForce GTX 970 G1 Gaming Ram: Kingston HyperX DDR3, 16GB Power supply: Cooler Maser GM G750M, 750W
Hdd: WD blue WD10EZEX, 1Tb

I use 2 BenQ Zowie RL2455 as monitor's.

When I play assassins creed my cpu gets up to 55 to 65 degrees celsius. I recently cleaned my pc with dust clearer stuff.

Do you guys, girls or others genders have any suggestions what the problem is. THANKS

Ps. I also posted this on r/gaming and someone sed I also should post it here.

Submitted December 31, 2017 at 12:33AM by fapppian http://ift.tt/2CrRoeA