So I made an iMovie of about 3GB, and am looking to burn it onto a DVD. Since the Mac I used to make the movie only has a combo drive, I put the movie onto an external hard drive successfully. When I try to open the video on another Mac, it sends me a message saying that this computer does not have the proper applications. What do I need to be able to open up the video on the new Mac? And also, if there's a way to burn the video onto a DVD from the original computer, that would also be much appreciated.