This example shows, how to draw application icon in the system tray. Icon in tray is not responding to any messages in this application. This icon is only picture, which appears, when application is running and hides, when application is closing. Don't forget to add ShellAPI in uses chapter.
uses ShellAPI; ... procedure TForm1.FormCreate(Sender: TObject); begin MyIcon.cbSize:=SizeOf(MyIcon); with MyIcon do begin Wnd:=Form1.Handle; uID:=0; uFlags:=NIF_ICON+NIF_TIP; hIcon:=CopyIcon(Application.Icon.Handle); end; Shell_NotifyIcon(NIM_ADD, @MyIcon); end; procedure TForm1.FormDestroy(Sender: TObject); begin Shell_NotifyIcon(NIM_DELETE, @MyIcon); end;