Minimize Semua Window

unit Unit1;

interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;

implementation
{$R *.DFM}

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;
end.