Problem With Compuer Freezing

[tufty]

So, few weeks ago I finished my first build. Since then I have had nothing but problems with it. It freezes at least once every 2 hours, but it can happen within a minute of start up. This problem is getting very frustrating.

Here are my specs:
Mobo: ASUS P8Z77-V LX
CPU: i5 3570K @ 3.4GHz
RAM: Corsair Vengeance Blue 4GB (1x4GB), 1600MHz, 1.5v
PSU: Corsair GS 700
Graphics Card: XFX HD 7970 Black Edition
HDD1: WD Caviar Blue 640GB (OS)
HDD2: Segate Barracuda 2TB
OS: Windows 7 Home Premium 64-bit

Here is everything that I have tried so far:
- Removing and re-installing RAM.
- Ran Windows Memory Diagnostics, default settings, PASSED.
- Ran memory in XMP Mode.
- Ran Intel CPU Diagnostics tool, PASSED.
- Ran Seatools HDD Diagnostics tool on both drives, all tests PASSED.
- Re-installed Windows, custom instillation.
- Downgraded catalyst drivers, and network card drivers

Can anyone give me another suggestion? Would installing another 4GB of RAM help? I’ve been told that 8GB is recommended for my system.

 

[Cyberat_88]

Take a course in computer hardware, get a compTIA+ certification, go back over your built and see what you did wrong.

 

[rgd1101]

When you say freeze, do you need to reboot the system, or it will response in a few seconds?

 

[tufty]

When you say freeze, do you need to reboot the system, or it will response in a few seconds?

Sorry, I should have been clear about what I meant. It stops responding completely, so I have to reboot. I did try leaving it for 10 minuets once, but it still wouldn't respond.

 

[Cyberat_88]

The only thing I do not see is Heat readings from bios as well as from windows. Other than that PSU voltage fluctuations, get voltage tested.
What voltage is the ram ? What voltage does the MB provide to ram by default ? Is your system OC-ed ?