Private Sub NotifyIcon1_DoubleClick(sender As Object, e As EventArgs) Handles _
  NotifyIcon1.DoubleClick
        Me.WindowState = FormWindowState.Normal
    End Sub
 
    Private Sub Form1_SizeChanged(sender As Object, e As EventArgs) Handles _
      Me.SizeChanged
        Dim isMinimised = (Me.WindowState = FormWindowState.Minimized)
 
        Me.ShowInTaskbar = Not isMinimised
        Me.NotifyIcon1.Visible = isMinimised
 
        If isMinimised Then
            ShowBalloon("läuft im Hintergrund weiter...", 1, 3000)
        End If
    End Sub
 
Sub ShowBalloon(Text As String, TipIcon As Int16, ms As Int32)
        ' 0 = None
        ' 1 = Info
        ' 2 = Warning
        ' 3 = Error
        'NotifyIcon1.ShowBalloonTip(ms, My.Application.Info.Title, Text, 
        ' TipIcon)
End Sub