The songs are gone or the playlist is gone? They will still be on your computer! If you create a playlist it's a good idea to save it if you want to use it again. And remember you can import LW's playlist into other players that use playlists.

Use your operating system search engine & you'll find where they are. Search for the name of one of them or if you can't remember, then search for .mp3

Oh yes I forgot by deleting your preferences folder your save & shared folders will be forgotten by LW. I normally suggest people to make a note of their settings before they delete the LW preferences folder. Well it will mean you will need to search to find which was your LW downld folder. Normally it's in the same directory as your incomplete folder. So search for your 'incomplete' folder & you'll find it. By default it's normally called 'Shared'. As for any other folders you might have been sharing, well you'll need to sort that one out. Probably ones that have mp3's in them.