type
  TDriveState = (DSNODISK, DSUNFORMATTEDDISK, DSEMPTYDISK, DSDISK_WITHFILES);

function DriveState (driveletter: Char) : TDriveState;
var
  mask: String[6];
  sRec: TSearchRec;
  oldMode: Cardinal;
  retcode: Integer;
begin
  oldMode: = SetErrorMode(SEM_FAILCRITICALERRORS);
  mask:= '?:\*.*';
  mask[1] := driveletter;
  {$I-}
  retcode := FindFirst (mask, faAnyfile, SRec);
  FindClose(SRec);
  {$I+}
  case retcode of
    0: Result := DSDISK_WITHFILES; { at least one file was found  }
    -18: Result := DSEMPTYDISK;    { no files, but disk is ok     }
    -21, -3: Result := DSNODISK;   { DOS ERRORNOTREADY in WinNT,
                                       ERRORPATH_NOTFOUND in 3.1  }
  else
     Result := DSUNFORMATTEDDISK;   { unformatted disk in drive    }
  end;
  SetErrorMode(oldMode);
end; { DriveState }