TL:DR - My computer is telling me Reboot and select proper boot device, It shows it in the bios but it will not load. I have reset the bios. I tried to look up a solution online it said change the sata mode from AHCI to IDE, but in my bios it only shows AHCI. I'm not sure what is wrong.
I just recently built a pc for my wife, I built it all and was still waiting on the cpu, so I decided to put my Intel Core I7 6700k to start installing and making sure everything was running fine, was running good for a weekend no issues, once I put the other cpu in it would randomly crash doing almost nothing. I did stress tests on it all temps were normal never crashed when doing them. It would just randomly crash.
CPU - Intel Core I5-6600k
Motherboard - Msi - B250 PC Mate ATX
Memory - Crucial - Ballistix Sport LT 8GB
Storage - Western Digital 1TB
GPU - MSI Geforce GTX 1060 3GB
PSU - 500W 80+ Bronze