It's quite possible that his recorder is using some odd format. Been there, done that ;).
You could try (paid) software such as Recover disc (meh) or ISO Buster (my fave) to see if anything is retrievable. Most of the free programs IME unfortunately don't do enough to get to the task at hand.
ok my dad has dumped another "geek savvy" project on me the last one was a breeze but i digress...he needs me to make copies of a dvd he made from an old vhs (its a family video perfectly legal in case you were wondering). but i am unsure of a few things mostly why when i put the dvd in my pc it shows no files and when i call it up in my video format converter still shows no file exists on the disc?!?! im wondering if his recorder records in an unrecognizable format for my dvd player? any help would be awesome