I recently upgraded a PC that is being used for general use and gaming. I chose an FX-4130 with retail heatsink and fan, paired with a Gigabyte GA-78LMT-USB3 (rev. 5.0) motherboard, which supports this CPU, and 8GB (2 x 4GB) DDR3-1600 RAM. All of the above parts are brand new, and nothing is being overclocked. Other parts include an NVIDIA GTX 560 Ti 1GB video card and Antec Earthwatts 650W PSU, both of which have already been giving trouble-free service. The PC is running Windows 7 Home Premium 64-bit.
All was going fine until I started getting random reboots at the oddest times -- not while running intensive 3D games or stress testing using Prime95 (stable in both cases), but while doing basic things like using Firefox normally. I could be scrolling or switching tabs and out of the blue, I'm back on the POST screen. Also, the application CoreTemp causes reboots consistently. After the PC reboots into Windows, I get a dialog saying a BSOD happened, always with the same bugcheck code of 0x124: WHEA_UNCORRECTABLE_ERROR. While not frequent, these random reboots happen every few days.
I tested with different, known-good RAM. Still reproducible. I then tested with another known-good video card. Problem still there. I am hoping someone on the forums can point me in the right direction as to a cause and a solution.
I did find this support article and wonder if I'm experiencing the same issue, although I don't use Steam:
It suggests upgrading your motherboard's BIOS to the latest available. Unfortunately, I am already running the latest BIOS version for my board (FA), and am still experiencing the issue.
PC 1: GA-78LMT-USB3 / FX-4130 / 8GB (2 x 4GB) DDR3-1600 / MSI R9 290X LIGHTNING / Antec EA650 / Windows 7 Home Premium x64 SP1
PC 2: M5A78L-M/USB3 / FX-6300 / 8GB (2 x 4GB) DDR3-1600 / MSI R9 290X LIGHTNING / Antec EA650 / Windows 7 Home Premium x64 SP1