I would think you would go into Control Panel - Folder Options - File types and remove 001 as a registered file type. That should remove the association.

Then, reboot. The computer should ask you what program it is supposed to associate with the file and when you don't choose one ... it won't open.

If you don't have any application opening it, however, how do you expect it to open at all?? When you say "so that the filetype 001 opens with nothing" ... what do you mean exactly??