You have not actually specified an icon to display in the task bar. Running your code in LINQPad, by simply adding notifyIcon.Icon = SystemIcons.Application before the call to ShowBalloonTip I was able to get the tip to be displayed. Also note that you should call Dispose when you are done with your NotifyIcon instance.
You would normally handle the MouseClick event to detect the click and call the ContextMenuStrip.Show() method: private void notifyIcon1_MouseClick(object sender, MouseEventArgs e) { contextMenuStrip1.Show(Control.MousePosition); } But that doesn’t actually work properly, the CMS won’t close when you click outside of it. Underlying issue is a Windows quirk (aka “bug”) that is described in this KB … Read more
You can either set notifyIcon1.Visible = false; OR notifyIcon.Icon = null; in the form closing event.