try this
private void Form1_Load(object sender, EventArgs e)
{
notifyIcon1.BalloonTipText = "Application Minimized.";
notifyIcon1.BalloonTipTitle = "test";
}
private void Form1_Resize(object sender, EventArgs e)
{
if (WindowState == FormWindowState.Minimized)
{
ShowInTaskbar = false;
notifyIcon1.Visible = true;
notifyIcon1.ShowBalloonTip(1000);
}
}
private void notifyIcon1_MouseDoubleClick(object sender, MouseEventArgs e)
{
ShowInTaskbar = true;
notifyIcon1.Visible = false;
WindowState = FormWindowState.Normal;
}