Thank you, that solved the problem although I believe I don't have two graphic cards, but it seems for some PhysX effects my system could use main processor and switching it only to Nvidia solved the problem

I just purchased the game on Steam and it seems I cannot play it; when I try to run the game, the screen goes black, I can see and move only the mouse pointer and the music starts playing, but that's all; the game is completely not responding, I have to switch to other tasks in order to shut it down...