(1) string ComputerName = "localhost";
(2) ManagementScope Scope= new ManagementScope(String.Format("\\{0}\root\CIMV2", ComputerName), null);
(3) Scope.Connect();
(4) ObjectQuery Query = new ObjectQuery("SELECT * FROM Win32_PnPSignedDriver");
(5) ManagementObjectSearcher Searcher = new ManagementObjectSearcher(Scope, Query);
(6) var result = Searcher.Get();
(7) foreach (ManagementObject WmiObject in result)
    {....}