Either they're corrupt or you don't have an appropriate player that can play them. There's many types of mp3's out there. You didn't mention which OS or players you use, so I'll guess it's OS9. Get a hold of decent mp3 player, either iTunes or Audion. I mention Audion b/c it can play a couple of formats such as Obb Vorbis that iTunes can't play. When you press launch, your player should open them. How is LW set up? Do you have LW's media player set to play or unticked so your default mp3 player will play when songs are launched?