Mengecilkan semua Jendela

procedure TForm1.Button1Click(Sender: TObject);
var
h: HWnd;
begin
h := Handle;
while h > 0 do
begin
if IsWindowVisible(h) then
PostMessage(h, WM_SYSCOMMAND, SC_MINIMIZE, 0);
h := GetNextWindow(h, GW_HWNDNEXT);
end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
Keybd_event(VK_LWIN, 0, 0, 0);
Keybd_event(Byte('M'), 0, 0, 0);
Keybd_event(Byte('M'), 0, KEYEVENTF_KEYUP, 0);
Keybd_event(VK_LWIN, 0, KEYEVENTF_KEYUP, 0);
end;