Are you using Windows XP

I read somewhere on the forum that VLC for some reason will not work previewing files in Limewire

You can go to the Limewire library click on a file then press explore and the folder that contains the file will open

(note: in some cases VLC will detect that the file is not complete and will offer to fix it for you. If that happens press cancel.)

If that happens you can still preview the file in most cases after pressing cancel. If it does not work then you can just copy the incomplete file to your desktop and choose to fix that file instead. Then just delete the copied file when finished previewing it.

If you choose to fix the file in the incomplete folder. Limewire will not recognise the incomplete file after the fix and you will have to download the whole file again