Steam games to small and in center of screen?

I'm using a Windows Vista computer and this problem just recently started. When I play any steam game, like Crysis, any of the Half Life games, Left 4 Dead, Garry's mod, etc, all of them are just in a little square in the center of the screen and are surrounded by a big black border. They aren't in windowed mode, they just don't take up the full screen, like their resolution is smaller. Here is an example of the Half-Life 2 menu when I start it up.



http://img197.imageshack.us/i/steamgmaes鈥?/a>



It's not in a window and there is no windows bar at the bottom so I don't know what the problem is. I asked this before but the answers, which consisted of "Change launch options to 'fullscreen'" and "I dunno", didn't help. Please help.Steam games to small and in center of screen?
Have you tried possibly going to the video options and selecting the proper resolution for your screen?



If not, try it.