PC Reboots Randomly while gaming?

[dommy.crazy]

I got a new PC, Everything seems to be working fine, the temperatures are fine, everything seems to be running smooth... But when I play games for a little while, then go to alt-tab or something along those lines, the PC just shuts down and reboots without warning and it's really worrying me

 

[ArchitSahu]

Full system specs?

 

[dommy.crazy]

Full system specs?

CPU: Intel i7 8700 6 core @ 3.2Ghz
GPU: Zotac NVIDIA Geforce GTX1080 8GB
PSU: Cooler Master 750 Watt Powersupply (I don't know the model, sorry)
Motherboard: ASUS Prime Z370-P
RAM: 16 GB DDR4 4400Mhz
SSD: 250GB (OS and a few games)
HDD: Seagate 2TB (For Games and Stuff)
OS: Windows 10