ok so i know this is obvious but it worked for me.
open limewire
go to help
click using limewire
click on help for the version you have
click on the lost lw or need update (NOT ON THE ENTER EMAIL FOR SUPPORT)
fill in email and click submit
click on the system you are running and step by step instructions come up. you may find it easier to print them out so you can go through it without moving windows out of the way.
THIS WORKED FOR ME HOPE IT WORKS FOR YOU.
GL