Instructions
Hard copy
Insert the "Thief: Deadly Shadows" disc into your computer. The disc should automatically load.
Double-click on "Setup.exe" it does not begin automatically.
Click "Install." Press "I Agree" to accept the license agreement.
Enter the directory you want the game to be installed in. This step is optional. You can let it install to the default directory.
Press "Next" in response to the following two prompts.
Press "Install" to install the game to your hard drive.
On-line version
Open "Thief: Deadly Shadows" in Steam. Press the "Add to Cart" button.
Press "Purchase for Myself."
Enter your payment information. An installation window will appear.
Press "Next" to start downloading "Thief: Deadly Shadows." The game automatically is installed once the download is complete.