I don't know about us guys b/c we don't work for LW. We're not LW Service Support, they're different. And I'm probably not the best person to answer this b/c I'm a mac person. However I can make some suggestions.
In this extreme case, make sure the incomplete files you're trying to delete don't have a file of the same name in your LW Dwnld window & dwnld folder. Were the files you deleted from the incomplete folder coloured red or black? Search your complete HDD to see if you have such named files anywhere else. It sounds mighty suspicious that you can't delete these files. It sounds as though these files are in use for some reason. I strongly recommend you do a virus and spyware check. Have a look at the following thread to see if there's any pointers you might be able to pick up on: http://www.gnutellaforums.com/showth...threadid=26903

Could you detail exactly how you went about deleting these files step-by-step?
Normally:
Firstly, they cannot still be dwnlding, 2ndly go to LW Library window & select your incomplete folder. Select the file you wish to delete & press the delete button. That should be it. However, depending on your OS & file protection software, you also 'might' need to quit LW before you can trash these files.

Hope these suggestions help you in some way, if not, get back to us in this thread. And an experienced Windows person can take a closer look at the issue.