If you have Windows 7, try this. . .

1) Open your Start Menu
2) Go to "Computer"
3) Open your (C:) drive
4) Open the file "Program Files"
5) Open the file "Steam"
6) Open the file "Steamapps"
7) Open the file "common"
8) Open your game file
9) Right click on your game launcher app and select open

I think that this, will open your gameif not then I'm sorry I couldn't help :/