Hi Mathews
Not sure why you don't have the Enqueue button it is located between Launch and Delete buttons. You have to highlight the song you want to enqueque for the enqueue button to be functional. You may have done that not sure.
This information would be helpful:
What windows version are you using?
What LimeWire version do you have?
What Java version do you have?
Have you checked out this link: Fixes for LimeWire
http://www.gnutellaforums.com/showth...threadid=36420