Problems shutting down computer, please help

Hi everyone.

I have been having some issues with my computer not shutting down correctly as it restarts every time I try to shut down. This has been happening since I first built it a week ago. What happens is that windows will initiate the shutdown sequence and shutdown the machine and everything inside will power off as I can see the all of the fans slowing down. However, all of a sudden, everything powers right back on again after a few seconds. Sometimes, the computer will fail to boot, quicking turning on but not being able to reach the boot screen, which may repeat once to three times. This occurs whether shutting down through windows or through pressing the power button. Also to note, the same thing occurs when trying to put the computer to sleep mode. Currently the only way to power the pc off is to hold the power button immediately after it shuts down to drain the power or to just turn off the power supply. Also to note, the computer has crashed once or twice over the past week for seemingly no reason. Otherwise, the computer itself appears to be working fine when turned on but I'm wondering if this problem is a sign of something more serious.

TL;DR - My computer won't shut down properly and restarts instead. Sometimes fails to boot and occasionally crashes.

I have tried the following:
- updating latest bios
- updating latest amd drivers
- installing all windows updates
- tested cpu and gpu stability using prime95 and furmark
- resetting cmos
- disabling all wake on lan, etc. and similar features on bios
- checking registry for poweraftershutdown value
- disabled boot after system crash (no BSOD)
- checked event viewer for errors, the only persisting error I found around time of shutdown/restart sequence was an error 1003 (which I found nothing on google) from ISCT Agent (Intel Smart Connect Technology)
- checked some bios settings outlined in other similar posts (forgot exact ones)
- checked wiring to front panel, although not really clear whether the orientation of the individual header matters as the mobo manual shows which is the + and which is the ground but the header for the case doesn't.
- checked voltages of each rail on voltage sensors (all well within acceptable ranges)

My computer specs are below
i5 3570k @3.4ghz (not overclocked yet)
ASRock z77 extreme4
G.Skill Ares 1866 9-10-9-28 @1.5v
MSI 7950 Twin Frozr @ 1050/1575 1.1v (problem occured before overclock so not due to this)
Force GT 120gb (has OS and programs)
WD Caviiar Black 1TB
ASUS cd/dvd drive
ASUS N15 wireless card
Corsair TX750 v2
running windows 7 64bit
probably doesn't matter but I have a carbide 500r case, a noctua nh-d14 cooler, and a Samsung Syncmaster 2233RZ monitor.

All help would be greatly appreciated on any ways I could resolve this problem. I could provide screenshots or more description of whatever may help diagnose the problem. It would be helpful to know whether this is hardware or software related, maybe psu is bad? Thanks in advance.

Just installed and tried to use it. It just shuts the computer down faster, still continues to restart as normal. Any other ideas anyone?

Thanks, I just got a chance to open up the case today, been a little busy the last few. The motherboard and video card capacitors all look fine to me, I didn't feel comfortable opening the psu so I didn't check that.

Come to think of it, the very first day I built it, before installing any software besides speedfan and 3dmark11 to get a quick benchmark, it shut down fine. Is it possible then that there is an issue with a driver or program of some sort? If so, how would I go about fixing that.

Also, my brother told me that he got a BSOD today when I wasn't home with a bad pool header error, first BSOD ever in the last week and a half, may or may not be related to the problem but I thought I'd point that out.