Ok, so I've upgraded recently from gtx950 to rx580 and I just removed old card, put in the new one, basically uninstalled old drivers, installed new ones, and it detected the GPU in that new AMD software that I got, also in Speccy, and also in System settings without any issues. I played some Dirt3(which is kinda old game), I put settings on maximum and average FPS was around 160, so my guess was that everything was fine. Few days after I downloaded pirated Mafia 3 and installed it and played it for 1 minute and my PC restarted. Then I downloaded NFS Payback from the same site and same thing happened. I should mention that while in game, if I remember well, both games were running just fine. Then I decided to reinstall the system fully and installed all drivers again and everything and the GPU was detected again, everything seemed to work fine. Then I downloaded Mafia3 but this time from Steam, and before opening the game I got the notification in little window that went something like "Your system does not meet(I think it said minimum) requirements to play this game, performance may suffer", so then I was like, that's definitely weird, cause my hardware is more than recommended for that game. Again after playing for few minutes, my PC shut down this time instead of restarting. For the record I have FX 8350 and 8GB of RAM(2x4). So, I'm pretty sure the problem is of hardware nature, I was thinking that It might be because I have 2 monitors, so I shut the one down, problem still remained, then I thought maybe the new GPU's coolers are on the opposite side and they're extracting all that heat directly onto my CPU, so I monitored the temperatures in Speccy and the loads of GPU, CPU and RAM in Task Manager on my second monitor, but again everything seemed to be just fine, but the PC still shut down(I should also note that when I turn it on after it shuts down like that GPU gets so loud for like 10 seconds while PC starts). So my last suspicion is my PSU, I don't know what is it(I'm not home right now), but I remember getting quality PSU just for those reasons(but like 5-6 years ago) and I think it's 600W(which I calculated is much more than enough to run my hardware) and I think it has high efficiency, so I'm thinking that I might've damaged its coolers when I was air cleaning my PC(because coolers are inside the box, I can't hold them not to rotate) but I'm not sure since I couldn't find a single software that monitors PSU's temperatures and coolers rotation. So if it's clear to someone from the given information what is the problem, any information would be valuable. Thanks