Windows 7 64 bit shuts down unexpectedly

Hi Everyone,

I installed Windows 7 Ultimate 64 bit on a new computer, most of the time when I turn my PC on, it starts checking the system and asks me to start Windows normally or in safe mode !!!! or sometimes unexpectedly shuts down and checks the system.... or sometimes nothing happens but when I start my PC next time, it does the same thing !!! then after starting the windows give me this message : " Windows recovered from an unexpected shutdown. Windows will inform you if there is a solution for this problem "
I even used the sleep option rather shut down ,but still get the same problem, most of the times.

Does anybody know what is the problem here? !! is this a software or hardware compatibility issue?
Please help me.

Think it's a hardware issue.. What procesor and how much RAM have you got?

did you do a custom install or an upgrade? have you applied all patches? are you using oem drivers for your hardware or windows native?

Custom install of Windows 7 Ultimate 64 bit

Motherboard: Gigabyte 790FXTA-UD5 AMD790FX ATX AM3 DDR3 3PCI-E 3-WAY CROSSFIRE X2GBLAN SATA USB3.0

Processor: AMD Phenom II x4 965 Quad Core Processor AM3.4 GHZ 8MB Cache 125 W 45NM

Memory: OCZ Gold OCZ3G1600LV4Gk 4Gb DDR3 2x2GB DDR3-1600 PC3-12800 CL 8-8-8-24 Dual Channel Memory Kit

Hard Drive: Western Digital WD10EARS Caviar Green 1TB SATA 64MB Cache 3.5IN Hard Drive

Video Card: Gigabyte GeForce GTS 250 OC 738MHZ 1GB 2.2GHZ DDR3 PCI-E DVI-I VGA HDMI Video Card