Thanx for replying..
I have tested all my pc parts and i found out that it is due to my graphics card(geforce 8500gt 256mb). What can i do to resolve the restarting issue? i have updated and it still restarts. The graphics card needs a 450watt power supply and i have a 460watt. it also requires 2gig ram for best performance but i only have 1.5gig. could this maby be the problem?