procedure WMActivateApp(var Msg: TWMActivateApp); message WM_ACTIVATEAPP;
  procedure WMSysCommand(var Msg: TWMSysCommand); message WM_SYSCOMMAND;
{©Drkb v.3(2007): www.drkb.ru}
...
procedure Form2.WMActivateApp(var Msg: TWMActivateApp);
begin
 if IsIconic(Application.Handle) then begin
  ShowWindow(Application.Handle, SW_RESTORE);
  SetActiveWindow(Handle);
 end;
 inherited;
end;
procedure Form2.WMSysCommand(var Msg: TWMSysCommand);
begin
 if (Msg.CmdType = SC_Minimize) then
  ShowWindow(Application.Handle, SW_MINIMIZE)
 else
  inherited;
end;