Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

procedure TForm1.Button1Click(Sender: TObject);
 var
    D: PChar;
 begin
    D := 'C:\*.*';
    SendMessage(ListBox1.Handle,
                LB_DIR,
                DDL_ARCHIVE +
                DDL_DIRECTORY +
                DDL_DRIVES +
                DDL_EXCLUSIVE +
                DDL_HIDDEN +
                DDL_READONLY +
                DDL_READWRITE +
                DDL_SYSTEM,
                Integer(D));
 end;

 //Oder: 
//Or: 

procedure TForm1.Button2Click(Sender: TObject);
 var
   D: PChar;
 begin
    D := 'C:\*.*';
    ListBox2.Perform(LB_DIR,
                     DDL_ARCHIVE +
                     DDL_DIRECTORY +
                     DDL_DRIVES +
                     DDL_EXCLUSIVE +
                     DDL_HIDDEN +
                     DDL_READONLY +
                     DDL_READWRITE +
                     DDL_SYSTEM,
                     Integer(d));
 end;