Как не допустить запуск второй копии программы 4

program Project1;

uses
  Forms,
  Windows,
  Unit1 in 'Unit1.pas' {Form1};

{$R *.RES}

var
  hwnd: THandle;

begin
  hwnd := FindWindow('TForm1', 'Form1');
  if hwnd = 0 then
  begin
    Application.Initialize;
    Application.CreateForm(TForm1, Form1);
    Application.Run;
  end
  else
    SetForegroundWindow(hwnd)
end.