Instructions
Set Up the Server
Open Windows Media Player on the computer acting as a media server.
Click "Library," then select "Media Sharing." Check the option next to "Share Media."
Select the boxes next to the devices with which you want to share the media. In this case, the PlayStation 3, then choose "Allow" to give the device permission to access the media server, then click "OK."
Scroll to the type of media you want to play on the PlayStation 3 from photo, music or video from the main menu, then select the file to play.