I don't think if you delete the 'Shared' folder you can have any files left on your system, unless they have introduced some new failsafe device into LW. But if you say they are there and they are complete...But I'm really sceptical on this. Maybe you mean all the new songs are in 'incomplete'.
Go to C:\Program Files\Limewire and create a new folder called Shared, then transfer all your files from incomplete to Shared. It should work OK.
When you launch LW your 'library' should be there again.
