System.Windows.Forms.Application.ThreadException += new ThreadExceptionEventHandler(Application_ThreadException);
            AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException);
            System.Windows.Forms.Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException,false);
 public static void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
        {
            log.Error(e);
            MessageBox.Show((e.ExceptionObject as Exception).Message, "Unhandled UI Exception");
            // here you can handle the exception ...
        }
        public static void Application_ThreadException(object sender, ThreadExceptionEventArgs e)
        {
            log.Error(e);
            MessageBox.Show(e.Exception.Message, "Unhandled Thread Exception");
            // here you can handle the exception ...
        }