public partial class FrmMain : Form
    {
        public FrmMain()
        {
            InitializeComponent();
            InitializeNetworkConnectionChecks();
            InitializeConnectionTimer();
        }

        private LyncClient client;
        private ConversationManager conversationManager;
        private Timer connectionTimer;
        private bool networkAvailable;

        private void InitializeNetworkConnectionChecks()
        {
            NetworkChange.NetworkAddressChanged += NetworkAddress_Changed;
            NetworkChange.NetworkAvailabilityChanged += NetworkAvailability_Changed;
        }

        private void InitializeConnectionTimer()
        {
            connectionTimer = new Timer
            {
                Interval = 1000
            };

            connectionTimer.Tick += connectionTimer_Tick;

            connectionTimer.Start();
        }

        private void CheckConnection()
        {
            CheckNetworkConnection();
            TrySetClient();
            SetConversationManager();
        }

        private void CheckNetworkConnection()
        {
            networkAvailable = NetworkInterface.GetIsNetworkAvailable();
        }

        private void TrySetClient()
        {
            client = null;

            try
            {
                client = LyncClient.GetClient();
                client.ClientDisconnected += Client_Disconnected;
                client.StateChanged += Client_StateChanged;
            }
            catch (Exception)
            {
            }
        }

        private void SetConversationManager()
        {
            if (client != null)
            {
                conversationManager = client.ConversationManager;
                conversationManager.ConversationAdded += Conversation_Added;
                conversationManager.ConversationRemoved += Conversation_Removed;
            }
            else
            {
                conversationManager = null;
            }
        }

        private void Client_Disconnected(object sender, EventArgs e)
        {
            CheckConnection();
        }

        private void Client_StateChanged(object sender, ClientStateChangedEventArgs e)
        {
            CheckConnection();
        }

        private void connectionTimer_Tick(object sender, EventArgs e)
        {
            CheckConnection();
        }

        private void Conversation_Added(object sender, ConversationManagerEventArgs e)
        {
            System.Diagnostics.Process.Start("https://www.google.com/");
        }

        private void Conversation_Removed(object sender, ConversationManagerEventArgs e)
        {
            // ...
        }

        private void NetworkAddress_Changed(object sender, EventArgs e)
        {
            CheckConnection();
        }

        private void NetworkAvailability_Changed(object sender, EventArgs e)
        {
            CheckConnection();
        }
    }