Maximum PC

Hey everyone. I'm dealing with a really bad computer freezing issue. No BSOD issue or slow processing issue, just a really annoying freezing issue. First off here are my specs:

SSD: 128GB OCZ Vertex 3
HDDs:1 TB Seagate 7200 SATA 3 (Windows Drive)
2 TB Seagate Green
500 GB Seagate 7200
500 GB Seagate 7200
PSU: 900 W Antec PSU
CPU:i7-960 3.20 GHz
CPU Cooler: Corsair H70 High Performance Hydro CPU Cooler
RAM: (4x 3) 12 GB Corsair Vengeance 1600 MHZ
MOBO: EVGA X58 SLI 3
GPU: 1 EVGA GTX 260
OS: Windows 7 Pro 64 Bit

Drivers are up do date on GPU and SSD and BIOS is up to date. I am not overclocking. Freezing happens at various CPU and RAM usage. Sometimes PC freezes on boot up, right after logging in, and it always freezes while watching a high quality video and/or converting video files. GPU temperature is normally at 60 C and maxes out at 65 C when playing a video and converting files. CPU stays at 29 C and the CPU cores are around 45 C.

History of PC Setup -

1. Tried OCZ Vertex 3 as boot drive. Turns out this SSD is infamous for having BSOD and instability issues especially with the sandforce/SATA 3 controller on my EVGA X58 MOBO.
2. I decided to make my 1 TB my boot drive and use SSD as programs drive. Still having freezing issues
3. Removed SSD from PC and installed programs on 1 TB drive. Still freezes.
4. Removed boot drive from SATA 3 and put it into regualr AHCI mode. Still freezes.
5. Put PC in IDE mode. Still freezes.
6. Updated drivers. Still Freezes
7. Cleaned the registry with Ccleaner. Still freezes.
8. Unplugged all HDDs but boot drive. Still freezes.
9. Set most BIOS settings to default

I'm out of ideas. I don't think this is a GPU issue, an HDD issue, a Windows issue, or an overheating issue with the CPU or GPU. The drivers that I think are crucial are up to date but maybe I'm missing something. I need advice because this is a really tiring issue and like I said, I'm out of ideas other than finding a new mobo.