LPCTSTR           lpDirectoryName              A directory on the drive whose free 
                                               space is to be returned
                                  
PULARGE_INTEGER   lpFreeBytesAvailableToCaller The number of free bytes available to the
                                               user
                                               
PULARGE_INTEGER   lpTotalNumberOfBytes         The total number of bytes that can be
                                               used by the user
                                               
PULARGE_INTEGER   lpTotalNumberOfFreeBytes     The total number of free bytes on the
                                               drive