[Help] need help with windows services stopping

 Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        Dim controller As New ServiceController
        controller.MachineName = "."
        controller.ServiceName = "Secondary Login"
        Dim status As String = controller.Status.ToString '- Error Object reference not set to an instance of an object.

        ' Stop the service
        controller.Stop()

        ' Start the service
        controller.Start()
    End Sub

Object reference not set to an instance of an object.