How do I register a CD Key to activate a product on Steam?
Please follow these instructions to activate a new retail purchase on Steam:
Please see the Retail CD Keys article for a list of games accepted for registration on Steam.
Ensure that you are activating your game through the Steam application. The Steam website cannot be used to activate a game. If you have not yet done so, you can download and install the Steam application by clicking on the green "Install Steam Now" button here: