Why does my pc turn off when playing games geeforce 250

Have you checked your CPU or GPU temps? If they're reaching into the 90s Celsius, chances are, that's the cause. Another cause could be the PSU being insufficient to handle the 250.

yes its running at 49degrees and i have a 550 watt psu

At 12 amps, a 550W PSU shouldn't have problems. Are you overclocking? Is Windows bring up the "Windows did not start normally" or "Your computer was shut down to protect itself..." messages? Have you tried updating your drivers? Does your computer turn off on its own outside gaming or while playing another game?

no the only time it turns off is when i run windows experiance rating half way through my comp does not display any message about the shut down
have updated my grahic card driver

A GeForce 250 is not a modern video card. You have heat problems,
Welcome to the NeW world of gaming!

have the latest drivers but it turns off when i run windows experiance i have not over clocked it

can you please sugest a good cool graphics card for oldish games not too dear

You want to run latet Games?
Pay the privr!

i had the same problem while playing ultimate spiderman the game didnt start and my pc restarted.i reinstalled my windows and the problem was solved