Swapping the files over IS NOT ILLEGAL. As long as the person using them owns both Oblivion and Skyrim if a program was made that ports the files over from an installed oblivion to an installed skyrim there is nothing that they can do. Because when they sell you the game the disc and all data upon it belongs to you. You may change/ add or destroy them if you so wish so long as, You do not copy them for distribution or make any profit from doing so. This is why you would be required to own the disc. But a piece of extra software that ports the files into the correct place would not be a problem. :thumbsup: