I bought a custom PC from a trusted guy on an old message board about a year and a half ago. Here are the specs:
CPU: Intel Core i7-2600K Sandy Bridge @ 3.4Ghz (Overclocked to 4.6Ghz) LGA 1155 95W Quad-Core Desktop Processor CPU
Cooler: CORSAIR CWCH60 Hydro Series H60 High Performance Liquid CPU Cooler
Mobo: ASUS SABERTOOTH P67 (REV 3.0) LGA 1155 Intel P67 SATA 6Gb/s USB 3.0 ATX Intel Motherboard
Video Card: MSI N580GTX Lightning GeForce GTX 580 (Fermi) 1536MB 384-bit GDDR5 Video Card
Memory: 16GB DDR3 1600Mhz Memory
Hard Drive: 240GB SATA III 6.0GB/s Internal Solid State Drive
Optical: 24x DVD-RW Burner
Power Supply: 650W 80 Plus ATX Power Supply
Case: LIAN LI Lancool First Knight Series PC-K57W ATX Mid Tower Computer Case
OS: Windows 7 Ultimate
It was serving me just fine for a while, and then about a year ago I started playing Fallout 3 and noticed that my whole system would just freeze mid-game. No BSOD, not ctrl+alt+delete functionality, just a total lock up and I'd have to manually power down. I thought it was a Fallout 3 issue so I applied some freeze fixes to no avail. The freezing would happen anywhere from 5-60 minutes in, but generally at some point within an hour in a given session it was likely to happen. Eventually I abandoned my play through.
Recently I've gotten into CSGO and the same thing happens, at some point the whole PC freezes. This has become annoying because I'm trying to get into competitive play and abandoning matches has a real bad effect on ranking up. Lastly, I tried playing Dota with my friend a few days ago and I froze 30 min in. So it's truly not game specific.
To make matters worse/more complicated, even though it's far more likely to happen in-game, the freezes happen during casual computing, too. In fact, they tend to happen out-of-game after my PC has been on for a long time (maybe 2+ hours), but sometimes during nothing more than Chrome browsing. Same total lock up kind of freeze.
Now, I was corresponding with the guy who built the PC about this issue when it first happened about a year ago and he wasn't very helpful. His theory was that maybe I need to de-clock, which I'm fine to do (CSGO nor anything else I'm doing requires 4.6 GHz), but I don't know how to do that. Other people have here and there offered it might be a overheating issue, but I'm disinclined. I don't know how to truly decipher all the info, but I've attached a SS from CoreTemp while running CSGO and it appears to be fine, no? Lastly, I thought perhaps it could be related to graphics card drivers? Perhaps I should uninstall them and reinstall them (is this possible), but again, it happens when I'm just casually computing as well.
CoreTemp SS: https://imgur.com/m7XSAgc
Thoughts? Help? Love?