Install Steam by downloading and running the Steam installer application located at SteamPowered.com. Steam is available for both Windows and Mac OS X computers. After downloading the program and creating a Steam account, you can purchase games to add to your game library and play. Steam is a service that sells and maintains video games and related software and video products.
Start by visiting SteamPowered.com, and then click the green Install Steam button in the upper right corner of the page. On the next page that appears, click the large green button that says Install Steam Now to download the Steam software program. Once the program has downloaded completely, open it to begin the Steam installation process.
In the installation window, click the Next button, accept the license agreement, and click Next again. Select the connection speed of your computer, and then select the default language. Finally, select an installation location. Once the installation finishes, click Finish to exit the installer.
In order to use Steam after it is installed, create a Steam account in the Steam application or website. If you already have a Steam account, simply log in to the new installation of Steam with your existing username and password.