I CAN'T PLAY DVD's!!! I am unable to play DVDs on my computer. A message in my InterActual player says: "The DVD navigator was not detected. If you don't have one installed, you will need to upgrade your system. Otherwise, try to reinstall your DVD Navigator." What the heck happened to my navigator?! I used to watch movies on my computer all the time. Know how to reinstall my DVD navigator? If not, WHAT DO?! HELP ME!!!!