Over the past month or so my computer has started shutting down with no warning and when it does, it seems to struggle with rebooting. It loads to the BIOS logo, shuts down, gets to the section where it asks if you want to boot in Safe Mode, shuts down, gets to the Welcome screen, shuts down, and so on. Sometimes it takes as many as seven reboots for it to finally boot to Windows. All I see in the event viewer is that "The system has rebooted without cleanly shutting down first" with no other Error or Critical listings in proximity.
I thought it might be that my processor or GPU was overheating, so I installed Real Temp and GPU-Z and had them create log files. My processor was running hot (46°-51°C idle, as high as 92°C under heavy load!), so I cleaned the grease Intel used off using ArctiClean and put some AS5 on, which did bring the temperatures down (38°-43°C idle, 73°C peak under heavy load). The GPU is rated up to 99°C but never goes above 80°C, even when playing Skyrim in 1920x1080 on Ultra.
It never takes the same amount of time for it to shut down, either. I've been able to run Saints Row: The Third for over 30 minutes, but then have it crash within 2 minutes of watching a 720p YouTube video. Another time I tried running E.Y.E. Divine Cybermancy in a 1024x768 window and it shut down after 10 minutes. Oddly enough, I can run Total Media Extreme and record with my Hauppauge HD PVR for hours on end with little to no trouble.
I've tried clearing the CMOS, running virus/malware scans (MSRT, avast! boot-time scan, Mbam, Kaspersky TDSSkiller, etc.), MemTest86+ and even formatted my hard drive (it's a few years old, it needed to be formatted anyways).
I've no idea what's wrong with my computer. I don't see any signs of damage on any of the components or my motherboard, but it might be something I can't see. And I've never tried overclocking because I know I don't have the proper cooling for it =P
Here's my setup:
OS: Windows 7 x64 SP1
Motherboard: EVGA Z68 SLI Micro LGA1155
Processor: Intel i7-2600 3.4GHz (Sandy Bridge)
GPU: NVIDIA GeForce GTX 560
RAM: G.SKILL Ripjaws X Series 8GB (2 x 4GB) 2133 240-Pin DDR3
PSU: Rosewill RV2-700 700W ATX12V v2.3
Thank you to anyone who may be able to shed some light on this! I know these types of questions get asked a lot, but I've no one else to go to, sadly.