Code:

procedure TForm1.Button1Click(Sender: TObject);

VAR

Wnd : hWnd;

buff: ARRAY [0..127] OF Char;

begin

ListBox1.Clear;

Wnd := GetWindow(Handle, gw_HWndFirst);

WHILE Wnd <> 0 DO

BEGIN {Не показываем:}

IF (Wnd <> Application.Handle) AND {-Собственное окно}

IsWindowVisible(Wnd) AND {-Невидимые окна}

(GetWindow(Wnd, gw_Owner) = 0) AND {-Дочернии окна}

(GetWindowText(Wnd, buff, sizeof(buff)) <> 0) {-Окна без заголовков}

THEN BEGIN

GetWindowText(Wnd, buff, sizeof(buff));

ListBox1.Items.Add(StrPas(buff));

END;

Wnd := GetWindow(Wnd, gw_hWndNext);

END;

ListBox1.ItemIndex := 0;

end;