My son has made some video's over the years from when he was like 6 to now 13. Some were for school and some just fun stuff playing in imovie. He burned them to disc thinking we could just re save them to the hard drive. We upgraded to a newer imac and I would like to be able to save these forever. How do I get these back on the hard drive? These were shot by him but I think there is something keeping them from re loadng onto the hard drive.