//need using System.Management;
    public class HardwareSerialNumber
    {
        public string GetDiskVolumeSerialNumber()
        {
            ManagementObject disk = new ManagementObject("win32_logicaldisk.deviceid=\"C:\"");
            disk.Get();
            return disk.GetPropertyValue("VolumeSerialNumber").ToString();
        }

        public List<string> GetCPUSerialNumber()
        {
            List<string> cpus = new List<string>();
            ManagementClass mc = new ManagementClass("win32_Processor");
            ManagementObjectCollection objCollection = mc.GetInstances();
            foreach (ManagementObject item in objCollection)
            {
                cpus.Add(item.Properties["Processorid"].Value.ToString());
            }
            return cpus;
        }
    }