Things You'll Need
Instructions
Connect the external hard drive to your computer via USB cable. Make note of the drive letter within Windows Explorer.
Open the Command Prompt by typing "cmd" into the Search box within the Windows Start menu. On Windows XP, select "Run" from the Start menu and type "cmd" to open the Command Prompt.
Type "format /FS:FAT32 A:" (replace "A" with the drive letter assigned to the external hard drive) and hit "Enter." Allow the utility to format the drive by typing "Y" to confirm the action. It will take a few moments to complete. Once done, exit the Command Prompt.
Open "My Computer," right-click the external hard drive and select "Explore."
Select "File>New Folder" and name the folder "VIDEO."
Move all the video files you wish to watch on the PS3 into the "VIDEO" folder. It will take some time to copy the files over. Once it has finished, disconnect the external hard drive.
Connect the external hard drive to the PS3's USB slot via USB cable. Turn on the PS3. You will be able to browse the external hard drive via the PlayStation's XMB (menu system). Navigate to the video file you'd like to play and press "X" on the PS3 controller to begin playback.