"Zombie Lab" It is the full version and download "Source SDK 2006" if so error install "Source SDK 2007" if yes an error "GameInfo.txt" entrants on the folder "Steam" C:\Program Files\Valve\Steam\SteamApps\username\half-life 2\hl2. and copy original "GameInfo.txt" and paste the the folder on "Zombie Lab" and enter the "GameInfo.txt" on "Zombie Lab" SteamAppId 220 in 215 believe that it actually works for "Steam" and I put a credit.