public string GetHDDSerial()
        {
            ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT * FROM Win32_PhysicalMedia");
            foreach (ManagementObject wmi_HD in searcher.Get())
            {
                if (wmi_HD["SerialNumber"] != null)
                    return wmi_HD["SerialNumber"].ToString();
            }

            return string.Empty;
        }