como executar somente 1 copia do programa

var hMutex:THandle;
begin
  hMutex := 0;
  try
    hMutex := CreateMutex(nil, true, PChar(´Meu Programa´));
    if GetLastError = ERROR_ALREADY_EXISTS then
    begin
      ShowMessage(´Meu Programa Já Está em Execução!´);
      CloseHandle(hMutex);
    end
    else
    begin
      Application.Initialize;
      Application.CreateForm(TForm1, Form1);
      Application.Run;
    end;
  finally
    ReleaseMutex(hMutex);
  end;
end.

var
aberto : HWND;
begin
 aberto := FindWindow(nil,PChar(´CroLan - Gerenciamento de Lan-Houses´));
  if aberto = 0 then
   begin
    Application.Initialize;
    Application.Title := ´CroLan - Gerenciamento de Lan-Houses´;
    Application.CreateForm(TfMenu, fMenu);
    Application.CreateForm(TDM, DM);
    Application.Run;
   end;
  end
 else
  begin
   ShowMessage(´Sistema já está em uso!´);
   Application.Terminate;
  end;