System freeze

Hi guys, i really need some help my system is hanging randomly i dont know why, im checking Voltages Tems and currents with everest ultimate, everything seems to be normal, i have done some prime 95 tests no hangs in 4 hours.

this is my set up:

EVEREST Ultimate Edition
Microsoft Windows 7 Ultimate 6.1.7600 (Win7 RTM)



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ACPI x64-based PC
Microsoft Windows 7 Ult
DirectX 11.0

QuadCore Intel Core i7 920
Intel Smackover DX58SO (1 PCI, 1 PCI-E x4, 2 PCI-E x16, 4 DDR3 DIMM, Audio, Gigabit LAN, IEEE-1394)
Intel Tylersburg X58, Intel Nehalem
4086 MB (DDR3-1333 DDR3 SDRAM)
DIMM3: A-Data 2 GB DDR3-1333 DDR3 SDRAM (8-8-8-22 @ 609 MHz) (7-7-7-20 @ 533 MHz) (6-6-6-17 @ 457 MHz)
DIMM5: A-Data 2 GB DDR3-1333 DDR3 SDRAM (8-8-8-22 @ 609 MHz) (7-7-7-20 @ 533 MHz) (6-6-6-17 @ 457 MHz)
BIOS Intel (04/14/10)
ATI Radeon HD 5850 Series (1024 MB)
ST3500418AS ATA Device (500 GB, 7200 RPM, SATA-II)
Coolermaster Cosmos S
Coolermaster Real Power Pro 850W
Coolermaster V8

no overclock
temps are normal no heating.

it is happenning every 7 days or something
perhaps de HDD ?

any help i will apreciate it.

i have a video on youtube, i catch this video while my son was playing a game.

thats kind of what happens, watching a video, reading a web page playing a game, w/e.

http://www.youtube.com/watch?v=1rXRl2kJiss



sorry for my poor english


Ty.