Instructions
Transfer your music or video files from your PC to a USB flash drive or an external hard drive. If you're using an external hard drive, make sure it is formatted to FAT-32.
Plug the flash drive or hard drive into an available USB port on the front of the PS3 console. Turn the console on.
Navigate to the appropriate application in the PS3's main menu. Select either "Music" or "Video," depending on what you want to view or listen to.
Highlight the USB device and press the triangle button on the PS3 controller.
Select "Display All" and your music or video files will come up.
Select your song or movie and press the "X" button to play it.