mklink needs the directory name available, not just an empty directory

One user was having some trouble with using mklink to redirect a folder to another drive. They had (seemingly) deleted its contents, but mklink still refused to make a link, saying that the filename was already taken. This is because mklink doesn't transform existing folders into junctions or symbolic links; it creates a new item with the given name. Deleting the existing folder should allow the creation of a new junction/link with that name.