protected void Page_Load(object sender, EventArgs e) { string MacAddress = string.Empty; try { ManagementClass MClass = new ManagementClass("Win32_NetworkAdapterConfiguration"); ManagementObjectCollection MobjCollection = MClass.GetInstances(); foreach (ManagementObject MObject in MobjCollection) { if ((bool)MObject["IPEnabled"] == true) { MacAddress = MObject["MacAddress"].ToString(); } MObject.Dispose(); } Response.Write(MacAddress); //if (MacAddress == "[ValidationAddress]") // return true; //else // return false; } catch (Exception ex) { throw ex; } }