Can't play the Portal 2, help.

[Berries and Cream!]

Is there anyway to change the games resolution outside of the game? When ever I start up the game it's just a black screen, I can hear sound but that's it. I'm pretty sure this is a resolution issue because I got a new Tv recently and some resolutions it won't play and will just produce a black screen.

[Nico]

mine (on computer) will start the menu but when i try to play a game (single and co-op) it restarts my computer!

[Rogue Diplodocus]

Have you tried windowing it. alt+enter when you have the black screen. I've had this problem a few times and this sometimes works

[Osmian]

somebody has a solution for this problem:
Invalid or corrupt background texture materials/vgui/portal2logo.vtf

i cant play and i've jsut bought the game