Civ 5 Not Launching After installing Gods and Kings

I have bought Civ 5 Gods and Kings DLC today, and after installing it, the game will not launch. The window in Steam comes up with Preparing To Launch, but after this nothing happens. I have looked at my status, and it said that I am currently playing Civ 5 but after few seconds it reverts back to online. I have tried many solutions to fixing this, and still no look. The game launched normally before installing the DLC, but after this it wont launch. I have tried checking the cache files, reinstalling the games, deleting the registry files, and still no luck. It seems that after installing the Gods and Kings something happened to the files. Unfortunately after reinstalling the game, I cannot even launch Civ 5 with no DLCs. Is there a way of downloading the newest version of the game somewhere else apart from Steam, and then launch it through Steam. The problem might be that Steam didn't download certain files, and the GFC doesn't detect that the files are missing. DXDiag http://pastebin.com/DyJmAShi