Gigabyte GA B75M D3V(F9) windows 7x64 shutdown incomplete problem

Hi guys,

help.

Perhaps this question already answered on any forums,
but I can't find decent answer to my problem.

I have a GA B75M D3V (bios version F9), paired with
Intel Core i5 3550 (Ivy Bridge), 2 x 4 GB Patriot Extreme DDR3 PC1600.

Installed Windows 7 x64 Ultimate SP1 on it.

Strange problem is, after using my computer for some time, perhaps an hour,
or more, randomly, I can't completely shutdown my PC.

After clicking shutdown on start menu, my PC react normal.
But, after a while, the PC (case and everything inside it) like in stall state.
and the monitor goes blank (no signal from the PC). So I have to press power button for 4 seconds to completely shut it down.

This problem randomly appears. I've just install my windows for about a week.

Any clue or idea of what might caused it ?

Thx

Could be hardware, but give this a shot first:

http://www.sevenforums.com/tutorials/1538-sfc-scannow-command-system-file-checker.html

ok, i'll try it.
thx for the reply.