pc hangs/freezes

my pc hangs/freezes when playing games, can be 5mins into game or 30mins.
no buttons work on mouse/keybourd have to use pc button to restart.

i have tryed different drivers for gfx card(clean install).currently 169.25. but still no difference
patched games,ms hotfixs, everything is upto date and its only a month old.

ive tryed 1x2gb ram still same, tryed 2x1gb same

dont think its heat as gfx card dont go above 58.c , cpu 46.c

have read loads on this but not resolved problem.

can anyone help PLEASE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Nzxt Apollo Blk
Asus P5N-E Sli
Intel Core 2 Duo E6850
Leadtek 8800gt 512mb
2x2gb Ocz ddr2 PC2-6400 Platinum(5-4-4-15@2.1v)
2x400 Sata2 Hard Drives Raid 0
750w Power
Vista Home Premium x32
Samsung SM931BW 19"Widescreen Monitor

 

I looked up your motherboard at the Asus web site, and there have been MANY updates released for the BIOS, and lots of them are for increased compatibility with memory modules, and others address CPU compatibility. The newest BIOS is only about a week old... it might pay to flash and update....
http://support.asus.com/download/download.aspx?SLanguage=en-us&model=P5N-E SLI
Be sure to follow their instructions CAREFULLY!

 

thanks for getting back to me.

i will look into that and try later so thanks and will let u no.

 

update on advice

flashed/updated bios etc and no change still the same ive even tryed the basic ram 2x1gb which come with it and its still the same.

any more suggestions PLEASE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!