I do not understand your question very well but it seems to me that you are developing a windows form application.
You could make a notification of the ones that appear in the taskbar with the code below:
NotifyIcon notifyIcon = new NotifyIcon();
notifyIcon.Visible = true;
notifyIcon.Icon = SystemIcons.Information;
notifyIcon.BalloonTipTitle = "Título";
notifyIcon.BalloonTipText = "Texto da Notificação";
notifyIcon.ShowBalloonTip(30000);
I hope I have helped. If that's not what you want, explain it better.