System crashes

[ghostdoggy]

hi,
i have a desktop PC with a 4870x2 graphics card,core 2 quad 2.83ghz 3Gb of ddr3 ram and a p5q3 mother board.operating temps @33 degrees for CPU and 45 for mother board when idle and 40 max for CPU and 55 for mother board with high load. by trial and error i found out that the crashes are not heat related.
i have also tried installing different OS. i have no idea what might be the problem...shall i look at my hardware again?

 

[hunter315]

what are you doing when the system crashes? Also have you run memtest?

 

[ghostdoggy]

well...it doesnt matter what i do....i might be playing a game or just open a folder or even do nothing at all.my system restarts (sometimes 2 times in a row).no problems with my memory mate..