Question my PC freezes after playing games for NO REASON?

May 7, 2019
i have a maximus iv extreme z motherboard
intel i5-3570k 4 core processor at 3.4ghz
nvidia gtx 780 gpu
8gb ddr3 1600mhz.
my power supply is a cooler master silent pro 1000w.
when i play fortnite or gtav ill be able to play for random sets of times but i always freeze, sometimes its been the game but other times my whole pc has frozen so i had to restart, the error codes among games say DXGI ERROR DEVICE REMOVED
- added a tdrlevel to the registry and that didnt work
-put in a 120gb ssd to run the os off of
-played around with quality settings
-tried to stress test with msi afterburner and froze
-sometimes i notice my cpu is at 100% usage when it freezes but not all the time and the gpu usage never even passes 80%
really getting frusterated i bought this pc off kijiji and i want to play games, if anyone can shed some light on how i can test or fix it id appreciate it thanks