Computer crashes at random times

with a new build i would start by looking at your mb bios and see if it up to date. a lot of new mb have cpu and ram code patches. i would then check if you have an ssd boot disk that the firmware is up to date. also post your power supply info and the cpu and gpu info. a lot of time reboots if there not a heat issue or a spot of bad ram then it a power issue. i would start with cpu-z make sure your mb set your ram speed up right. (read the ram spd info to see you ram rated speed and voltage).
download hardware monitor and check your cpu and gpu temps. intel idle cpu temp should it 30-45c range. I would also download memtest and run it to see if you have any bad ram. before i did this with the pc off and unplugged check that the ram is seated and in the right ram slots. same for the hard drive and sata cables. most mb have two sets of sata chipset make sure your drives are connected to the intel/amd sata chipset. I would also update your drivers the ones on the mb cd are old. intel chipset drivers...