Instructions
Connect the USB flash drive to any available USB port on the Xbox.
Turn on the Xbox. Select the "My Xbox" tab, "System Settings" and "Memory" in that order. A list of hard drives and similar devices will be listed. Select the USB flash drive that you have connected.
Select "Videos" and the MPEG video that you want to copy. Select "Copy" and the hard drive you want to copy the MPEG file to. Do this until you have copied all of the MPEGs onto the appropriate hard drive.