When I try to play Portal 2, it only gets as far as the first loading screen before the main menu. I have seen many people with this same problem in the past couple of days. They all have the same result: Nothing works. I have tried re-validating nearly everything, uninstalling and re-installing, re-starting steam, restarting my computer. NOTHING WORKS! This is really strange because all my games are working. Except Portal 2. The funny thing is that some sort of update cam out yesterday when I first tried to open it telling me about some new function of steam. I don't know if that caused it or not. Anyway, any help is greatly appreciated.