Cannot Delete or Move certain files

When trying to delete or move certain files in our file
system, (even files we just created) we often get an error
that states:

Cannot Move/Delete File or Folder

Cannot move/delete (filename). There has been a sharing
violation. The source or destination file may be in use.


We used to have a NT 4.0 Server and we would use
FileManager to close all open instances of the file and
then we could delete/move it, however, we are now using a
Win2K Server and FileManager no longer exists. We are...

Cannot Delete or Move certain files