i have proplem with my gtx260 vga when iam playing games like crysis or any other high graphic games after period ifind my pc is restarting ihave intel e8400 processor and power supply hec 450watt 4GBRAM MOTHERBOARD ep41
the heat is normal
You need a new Powersupply.
The system i use has a overclocked E8400 and a ATI 4830, and i use a 600watt powersupply.
For you i would strongly recommend a 600+ wattage PSU. Since the cards normal requirements are 600watt anyways. Just remeber to buy from a good brand, also for future proofing reasons getting a 700-800watt powersupply would also not be a bad idea.