Instructions
Turn on the Xbox 360 and eject the disc tray. Wait for the Dashboard to load, then insert an Xbox 360 game DVD. Close the tray and allow the game to be read by the system.
Press the "Y" button on the controller and the game's installation menu will appear. Use the analog stick to select "Install Game to Hard Drive," and press the "A" button on the controller. The game will be downloaded to the Xbox 360 using the Dashboard's software.
Wait for the game installation to complete, then restart the console. Wait for the Dashboard to load again. You can then use the Xbox 360 Dashboard to load the game you just installed to the hard drive. Select the game from the main menu that appears as soon as the console is turned on.