Handling a click over a balloon tip displayed with TrayIcon's ShowBalloonTip()

I think you mean NotifyIcon . Use following pattern...

NotifyIcon notifyIcon = null;
public Form1()
{
    InitializeComponent();
    notifyIcon = new NotifyIcon();
    // Initializing notifyIcon here...
    notifyIcon.BalloonTipClicked += new EventHandler(notifyIcon_BalloonTipClicked);
}

void notifyIcon_BalloonTipClicked(object sender, EventArgs e)
{
    // Operation you want...
}

I hope it feed your needs...