Instructions
Connect to Windows Media Player
Download the latest version of Windows Media Player for your computer. When the download completes, open Windows Media Player.
Navigate to the "Library" tab, then click the arrow on it. Click "Media Sharing," then "Share My Media To." Select the Xbox 360 from the list of devices shown. Click "Allow" and "OK."
Turn on your Xbox 360 and select the "Media" menu from the main menu. Choose either "Music," "Videos" or "Pictures." Select your computer from the list, then choose a file to view or play.
Connect to Zune
Download the Zune software to your computer. Launch Zune.
Click "Settings," then "Software" and "Sharing." Click "Enable Media Sharing with Xbox 360."
Enter a name for your media collection, if desired. Choose the media types you want to stream to the Xbox 360. If you have multiple 360 consoles, choose whether you want to stream content to all of them or only one. Click "OK" when finished.
Turn on the Xbox 360 and go to the "Media" menu. Select "Videos," "Music" or "Pictures." Choose your computer from the list, then select a file to play it.