The following code is a working example for determining the MAC address of your network card.
Imports System.Net.NetworkInformation
Public Class Form1
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
MessageBox.Show(getMacAddress)
End
End Sub
Function getMacAddress()
Dim nics() As NetworkInterface = NetworkInterface.GetAllNetworkInterfaces()
Return nics(1).GetPhysicalAddress.ToString
End Function
End Class