When I start the game from steam and the start button, the screen just turns black and never loads. My computer is over the recommended specs, and I am on a Windows Vista 64 bit.
It sounds as if you tried to run it in DX8 mode or something. Try starting it in dx 9.0 or 9.5 in the launch options.
For me it only went black when I tried to join a server with DX 8.0 but I was able to start the game.
add -autoconfig as a start parameter, start the game. If it starts now, remove the -autoconfig parameter again because it won't let you configure stuff yourself anymore.