To run Valve Source games, like Counter-Strike:Source and Team Fortress 2, follow the steps below:
- Make a note of the screen resolution of the monitor you will be playing the game on. You can find out your screen resolution by selecting the "Start" button --> Control Panel --> Display. In Windows XP, you should see the resolution listed there in a format similar to (1920 x 1080). In Windows 7, you will first need to select "Screen Resolution" in the left sidebar first.
- Open your Steam Library and right-click on the game you would like to run in window mode. Then select "Properties."

- Select the "Set Launch Options..." button.
- Enter the following text in the text box: -window -noborder -novid

- Select the "OK" button to close the "Launch Options" window.
- Select the "Close" button to save the changes.
- Launch the game and navigate to the options menu. Click on the video tab and verify that the resolution is set to the one noted above.
- Close the options menu.
You are now set to run your source game in full-screen windowed mode! This will allow you to alt-tab easily while in game, which can come in handy with a multi-monitor workstation! Repeat this process with other Source games to achieve the same effect! If you are having trouble, the following YouTube video may help: http://www.youtube.com/watch?v=Kdl-wSv5xL4




