System locking up, nor bsod

[FAZZG]

So in the last couple of days, my computer has completely locked up. I'll be in the middle of something and the it just stops responding. No error message, no BSOD, no event logs, it just locks up, and only a hard reset works to get it on again. The only things that were going on at the time were Firefox on youtube, a skype call, a game at max settings, and windows media player. I've done dskchk and the windows memory test and as far as i could tell, both of those passed. I also did memtest86 with two passes, and also used seatools for both the short and long test, which also passed. The only thing I installed recently was Photoshop, and amazon music. I removed those earlier today.
System specs are
i5 4670k
GIGABYTE Z87X-UD3H
Seagate 2Tb hdd
EVGA GTX780 acx
2x4gb g.skill ram
corsair hx750 psu

 

[johnbl]

(disable any overclocking, update bios, confirm the system is not overheating)

generally when a computer "locks up" the system will be deadlocked in code used by the graphics processor.
generally, you have to update the graphics drivers directly from the vendor (amd or nvidia) so give that a try.
You might also want to disable all high definition audio devices that don't have a speaker connected to them.
(use control panel, device manager to disable the devices)

I have also seen "lockups" that were caused by firmware bugs in certain solid state drives but they are becoming more and more rare unless you use a older SSD drive and fail to update the firmware.

after you update the graphics drivers, if you still get the problem you will want to force a bugcheck when your system locks up. This will create a memory dump that will show what the system is waiting on. (google how to force a memory dump using the keyboard to learn what to do)

So in the last couple of days, my computer has completely locked up. I'll be in the middle of something and the it just stops responding. No error message, no BSOD, no event logs, it just locks up, and only a hard reset works to get it on again. The only things that were going on at the time were Firefox on youtube, a skype call, a game at max settings, and windows media player. I've done dskchk and the windows memory test and as far as i could tell, both of those passed. I also did memtest86 with two passes, and also used seatools for both the short and long test, which also passed. The only thing I installed recently was Photoshop, and amazon music. I removed those earlier today.
System specs are
i5 4670k
GIGABYTE Z87X-UD3H
Seagate 2Tb hdd
EVGA GTX780 acx
2x4gb g.skill ram
corsair hx750 psu