I've been getting this issue since I updated my motherboard BIOS from it's initial version, which I'm going to assume was F4 as it's been a while but I truly don't remember, to F7 and an F8a BIOS Gigabyte support gave me to try and resolve issues with graphics card compatibility.

It seems that whenever the intel graphics accelerator on my Core i5 4670K is disabled, set to a power saving mode, or has intel HD graphics drivers installed, I'll get these freezing crashes, usually within 30 minutes of either booting into Windows or installing intel HD graphics, that require a force reboot. When this happens, and I press my hard reset button, my computer will shut down for a few seconds before starting up again, much like when updating a BIOS or maybe overclocking the CPU.

Now, I've been safe from this issue if I just leave the IGP enabled constantly and don't install drivers, but I guess I finally got off my butt and decided to ask around about this issue, as this seems to be subject to me and my setup. This issue has persisted through a PSU upgrade, and through Windows 8.1 to 10.