Hi jaiden,
To get limewire to show the license warning again, Start Limewire and go to Tools>Options>Searching>Basic> and tick the box that says "Show License Warning" then click apply. After that try to d/l something and when the License warning pops-up tick "always use this answer" then click "yes" and you should be able to download again. For mor info and a picture go to this link:
license problem
To change back to your default media player, in Limewire go to Tools>Options>Player> untick the box that says "Use LimeWire Media Player" then click apply. You should be back to using Windows Media Player
.