Hello and I'm geting a black screen whenever I load a level it freezes turns black. It's says it's got to do with graphic acceleration failing however, the first time I played the game,it worked and I could play all the levels if I wanted to. I am able to run other source games. I have reinstalled the game, quit steam and reopened it, Disabled steam community, run the game in it's lowest settings,uninstalled and reinstalled steam and even update my drivers.
I am currently using Mobile Intel(R) 4 Series Express chipset family. Pretty suckish I know but it's built into the motherboard.
I can run other source games and I was able to get portal running first time round.