Hi!

It's been about half a year since i had played day of defeat source on my laptop, and at that time it was running trouble-free. But recently i tried again. It ran very well, but after about 15 minutes my screen became black and could not do anything. I pressed the on off button and the pc shut down. I tried again and the same thing happened.
The laptop is a Sony VAIO vgn-FW51MF

Specs:

Processor: Intel core2 duo p8700 @ 2,53 GHz

Memory: 6 GB DDR2 ram

Graphic card: ATI Mobility Radeon HD 4650

What should i do?

CSS does the same thing.