If you have the disc version of a game that uses Steam and it is trying to install the game as a download, please follow the instructions below:
Launch STEAM and click the 'My Game' Tab.
Right click on the game and select 'Delete local content'. The non-installed information will appear next to the game.
Right click Steam on the task bar and select "Exit Steam".
Insert the install disc into your DVD drive and select Autorun.
From the Windows Desktop, open the Start/Window menu.
Open "Computer" (or "My Computer" depending on Windows version).
Right click the install disc and select "Explore".
Depending on the title the install executable's name may differ. Most games call it "setup.exe", though "run.exe" and "install.exe" are also somewhat common.
Double click the install executable and follow any prompts or instructions. Steam may ask you to log into your account. If it asks you how you wish to install the game, choose the "local" or "disc" installation option.
At the end of the installation process, Steam will connect on Internet to download the most recent updates which may take some time depending on your connection speed.