Got Nero burning with the IO Magic external DVD+RW I ordered through Dell. Working my way through it and downloaded and burned 3 movies.  The movies will play on the installed Nero Showtime, but will NOTplay on my other DVD player.  I get an error message on the screen.  Also will not play on my portable DVD player......shows me file folders but you cannot open them.  Also, the Nero Showtime has set itself up as the default media player.  Does anyone know how I can get the list of choices so I can pick which one I want to use?  Grateful for any information you can give me.  I am not very technical...........but want to learn.  Hoping to hear from someone.  Thanks