computer restarts its self and all games crash

[cal0002]

Hey ive got a Amd quad core phenom 2300, with 2 gig ram and 8800gts, i have recently braught it as old computer was restarting itself crashing to blue screen. This new one does exactly the same thing the only piece of hardware that hasnt been replaced is the ram HELP please, all games crash to i just need to know for sure that its the ram

[usasma]

Run a memory diagostic (free from here: http://www.memtest86.com/ )
Follow the directions precisely and let the test run for a minimum of 3 passes (overnight is better). If it starts spitting out errors you can stop the test immediately.

Post back with your results (and the rest of your system specs) and we can work from there.