Windows 8.1 Nx64 Random Freeze - Internet and Games

Okay, I'm getting this issue and it seems bother me for a long long time. My desktop randomly freeze (often in browsing and playing any games). I did reformat my PC for, I think 7 to 8 times, buying new PSU, new motherboard and processor, update all drivers and even do the FurMark and MemTest86 for many times even leave it for overnight but still the problems exist. What can I do again?

My specs :

Windows 8.1 N x64
6GB Ram
Radeon HD 6950 Graphic card
Seagate 320GB HDD
MSI 970A-G43 Motherboard
PSU 580

Check the event log for any error messages.

Run a graphics card testing tool (MSI Afterburner/MSI Kombustor) to see if your graphics card is causing this.