The Half-Life 2 Virtual Video mod can be launched using either of the following methods:

• Launching via the Steam client. Allows the user to load maps and change settings on the fly. Useful when testing different scenarios.
• Launching via the command line. Launches a map with a single command line. This approach can also be used to launch the game from a remote machine.

Launching Via Steam

• Launch the Steam client from the desktop icon or the start menu at Start->All Programs->Steam->Steam.
• Open the My games tab. This will bring up a list of available games including Virtual Video as shown below.

• Select Virtual Video and click the properties button.
• In the Virtual Video - Properties window, click Set launch options ....
• Set the following options in the Launch Options - Virtual Video window:
  
  -console -dev -windowed -w 640 -h 480 -nosound
  
  This will cause Half-Life 2 to launch in a 640x480 window with the developer console enabled and sound disabled. Note that this configuration need only be performed once.

• Back in the main Steam window, double-click Virtual Video or click the Launch button to launch the mod.
• Once the game has loaded, the developer console with appear as shown below. Load a map by entering map map_name on the console command line. A list of available maps automatically appears when the map keyword is entered (see figure). If you have already downloaded the Source SDK, a good map to start with is sdk_d1_trainstation_02 (you will need to compile this map first using Hammer, see the Hammer Tutorial).

• After loading the level, Half-Life 2 captures your keyboard and mouse to control the in-game player. Use ALT+TAB to shift the focus to a different application and allow the game engine to continue running in the background.
• To load a different level, open the developer console by hitting ESC and use the map keyword as before.
• To close Half-Life 2, open the developer console and type quit.

Launching Via Command Line

• Open a command console (Start->All Programs->Accessories->Command Prompt).
• Type the following command to launch Half-Life 2:
  
  "C:\Program Files\Steam\steam.exe" -applaunch 220 -game "C:\Program Files\Steam\SteamApps\SourceMods\Virtual Video" -dev -windowed -w 640 -h 480 -nosound +map map_name
  
  This will launch the Virtual Video mod with the map map_name, in a 640x480 window with sound disabled. Available maps are listed in the directory C:\Program Files\Steam\SteamApps\user\half-life 2\hl2\maps, where user is your Steam username.
• You can also put the above command line in a batch or script file, which allows the mod to be launched remotely or from within another application.
• After loading the level, Half-Life 2 captures your keyboard and mouse to control the in-game player. Use ALT+TAB to shift the focus to a different application and allow the game engine to continue running in the background.
• To close Half-Life 2, open the developer console and type quit. If the mod was launched remotely, close the game by killing the appropriate process.