OCZ ModXStream Pro 700W Modular Active PFC Power supply
SPINPOINT F4 320gb 7200RPM SATA
I need to mention that I have tried different memory configurations (changed them around in slots as recommended on mobo manual).
I have formatted hard drive and reinstalled windows with all latest drivers.
Restored default bios settings
System was taken to the store, they have tested it for 24hrs without fail...
anyone any ideas, I am pretty close to returning it back to the store
Try one RAM stick at a time, and run Memtest on it. One stick may be flaky.
Somewhat less likely, but still possible, you could also have a bad PSU, that is spiking your system or otherwise out of spec.