Hello all, ever since I upgraded my brothers PC its been blue screening on startup. This has been happening for months now and hes reinstalled windows to try and fix everything but now hes having issues with the task bar getting locked and not responding in addition to the blue screens on start up. Hes run mem tests and windows memory diagnostic and both came up with nothing. Hes moved the ram around and tried under and over clocking. He's also noticed that it only blue screens after a couple hours of the PC being off. If the PC's off for a couple minutes after its been turned on then its fine. He's reformatted three times now, thanks for any help you guys can offer.
SPECS
i5 6600k
Gigabyte GA-Z170-HD3P
2x8GB Corsair LPX 2400Mhz
EVGA 600B
R9 280 Dual X
x2 HDD