I have two TZTLF I am finally just getting around to updating to V8. In down loading part two to USB drive I forgot to format the USB drive. It still had the files from V7 on it. I got a message saying files were already on the drive, exact duplicates. Question is can I use the old files for part two? Are the files from V7 to V8 part two the same? Does Furuno have preloaded media with the files on it for purchase? Thank you in advanced to any one who will help.