Things You'll Need
Instructions
Purchasing and Downloading New Games
Power on your Xbox 360 and sign into your Xbox LIVE account. This takes you to your dashboard.
Navigate your way to the Games Marketplace and enter it by pressing the green "A" button.
Peruse the selection of Xbox LIVE and Xbox on Demand games. When you find one you want to download, select and purchase it.
Allow upwards of an hour for the game to download to your hard drive. When complete, go to your "Games Library" screen and select your game to play it.
Installing Owned Games
Insert your game disk into your Xbox 360 console. Opening the tray powers on the Xbox automatically.
Sign into your Xbox LIVE Account and, once you reach your dashboard, navigate to your Games Library.
Select the game in your tray. This will bring up the game-centric menu screen.
Select "Install to Hard Drive." This begins the process of installing the Xbox 360 game onto your hard drive in a process that takes--on average--about five minutes.