Pc freezes at random times

Hi.

My pc is a real pain and i suspect that one or more of the hardware is malfunctioning .
What happens: My pc freezes .IT does not run out of memory, all temperatures are normal ( some even lower than average according to speedfan ) i even booted in safe mode with networking and the damn thing froze.

When it happens : This might not have to do anything with the reason but it mostly happens when my Steam is updating or downloading games , but i have noticed that it "MUST" happen if i am not moving my mouse . Sometimes steam isnt even open and i just try to get in my browser ,it opens up and ...boom, frozen and so far THE ONLY option has been a hard restart after which i get the message if i want to "Run setup or start normally" and then the options for Safe mode, with networking, normal mode etc and after that it boots up to desktop. A few times my google chrome started using a lot of memory ( example, the highest currently is 90k and when i noticed that process was using 2.9GB of ram ).

I really do NOT know what to do. Open to suggestions.
Was planning to take it to the shop tomorrow but wanted to see if i can get some help here first.

EDIT: added a photo of what i believe is the event that happened during the freeze.

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