When you preview a file using LW, it creates a special preview file stored in the incomplete folder. eg: PREVIEW-my movie.mpg, so I would recommend deleting these preview files.

There's times when some files you downld create multiple incomplete files. I suspect it's something to do with being from different sources or the hash of the original file has changed (perhaps the id3 tag has been adjusted) so LW then no longer uses it & creates another (I suspect it may use part of what was already downlded) but I'm only guessing. As Sphinx suggested, once you've completed the downld you can get rid of any extra incomplete files of that title. But again be sure it was one you have already downlded. I would also suggest you delete the file by opening the incomplete folder manually (use the Explore button) & sending the file to the recycle bin. Too many people make the mistake of deleting the wrong files when deleting via the LW Library window & since doing that way by-passes the recycle bin, it's a dangerous method if you accidentally erase the wrong one.