Computer locking up at random times

[hugo999]

I have a problem with my computer that has been occuring for probably 2 years but has slowly began to occur much more often. The computer screen will simply freeze. the mouse cannot be moved, any sound playing will turn into a buzzing noise, the keyboard does not respond to inputs and the hdd led will stop flashing. this occurs whilst gaming, during normal use searching internet/word docs and even when it is not in use (come back to it frozen). the computer never blue screens or any other form of crash. i have checked windows event log to no avail. these crashes occur randomly, it might be within 5 minutes of logging into windows or the computer may go a whole day or two without crashing. It appears to happen more often just in windows not games but this is likely due to the lesser amount of time i spend gaming lately.

I recently changed the processor from an old phenom to the new 8 core processor and this problem has persisted, and become worse with time. The crashes appear to occur more often once the computer has initially turned on, once it has been on awhile it does not lock up as often.

to offer a solution to what the problem is i have done several tests:
prime95- does not crash at all, no errors
furmark- no artifacts
memtest86+- sometimes gets an error, restarts every time within 3 minutes, running from CD

I have tried swapping parts from a second computer without issues- graphics card, power supply and ram and memtest86 still restarts and reads errors in the exact same way. i have not been able to run windows with these parts for any significant amount of time to check stability there however

The system has been overclocked before (CPU, GPU and RAM) however the problems occur regardless of settings and voltages. The processor and graphics card are water cooled, and the system is in a well ventilated case, temperatures are consistently low.

Here are my system specs:
Crosshair V formula (2 yrs old)
AMD 8350 (few months old) -> originally 955 phenom quad core
2x4gb 1333mhz cl7 g.skill ripjaws (4 yrs old?)
500gb western digital hdd (4 years old?)
amd gigabyte 6870 1gb (3 years old?)
tx-850 850w corsair supply (2 years old) -> had a 550w power supply before this that died on me whilst in use, cannot remember if it happened with that one however
windows 8 64-bit (upgraded from windows 7 a few months ago, problem occured also with previous install)

If anyone could shed some light on this or offer any suggestions to troubleshoot it would be very much appreciated. Most of the parts are still within warranty so i can RMA them, however i am unsure of which part is even causing this problem.

 

[imkvn]

I think it's your HDD. Everything else you validated. I think its just reading slow.

 

[hugo999]

Thanks for the reply. To elaborate on the hard drive, the problem has not always existed for this build. The hard drive was bought with the original parts several years ago including a different motherboard, graphics card, ram, power supply etc. It seems to have began occurring in the past two or so years only, with the newer parts that i upgraded the system with (power supply, motherboard, graphics card), though i cannot pinpoint exactly when it began. I question if the restarting whilst not booted into windows (during memtest86 from a disc) would rule out the hard drive or any driver/software related problems also? I did an error test on the hard drive yesterday which came back positive with errors and these were fixed, however the problem persists both in and out of windows

 

[hugo999]

Well its still freezing up. I did a bunch of hardware diagnostics the past few days but have not been able to come up with anything wrong.. have gone through and updated all relevant drivers