¿Cómo obtener una lista de servidores SQL disponibles usando el código C#?

string myServer = Environment.MachineName;

DataTable servers = SqlDataSourceEnumerator.Instance.GetDataSources();
for (int i = 0; i < servers.Rows.Count; i++)
{
    if (myServer == servers.Rows[i]["ServerName"].ToString()) ///// used to get the servers in the local machine////
     {
         if ((servers.Rows[i]["InstanceName"] as string) != null)
            CmbServerName.Items.Add(servers.Rows[i]["ServerName"] + "\\" + servers.Rows[i]["InstanceName"]);
         else
            CmbServerName.Items.Add(servers.Rows[i]["ServerName"].ToString());
      }
  }