Preview files will show up in your incompletes folder. These files are created everytime you preview a file that's dwnlding.
For shared folders: Go to LW's menu Tools-Options & Saving & re-select your original LW Dwnld folder. Make a note of its name, location & path & then go to Tools-Options & Sharing & add this folder to your shared list.

I'm not a windows user, but if you right-clicked & stopped sharing your files, can't you reverse that by right-clicking to reselect your previously shared folders?

Also see these 2 threads: http://www.gnutellaforums.com/showth...threadid=25314

http://www.gnutellaforums.com/showth...threadid=27853

(For macosx that's prefs & Saving/Sharing & for OS9 that's Options & Saving or Sharing.)