public static string BHOKEYNAME = "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Browser Helper Objects";

        [ComRegisterFunction]
        public static void RegisterBHO(Type type)
        {
            RegistryKey registryKey = Registry.LocalMachine.OpenSubKey(BHOKEYNAME, true);

            if (registryKey == null)
                registryKey = Registry.LocalMachine.CreateSubKey(BHOKEYNAME);

            string guid = type.GUID.ToString("B");
            RegistryKey ourKey = registryKey.OpenSubKey(guid);

            if (ourKey == null)
                ourKey = registryKey.CreateSubKey(guid);

            ourKey.SetValue("Alright", 1);
            registryKey.Close();
            ourKey.Close();
        }

        [ComUnregisterFunction]
        public static void UnregisterBHO(Type type)
        {
            RegistryKey registryKey = Registry.LocalMachine.OpenSubKey(BHOKEYNAME, true);
            string guid = type.GUID.ToString("B");

            if (registryKey != null)
                registryKey.DeleteSubKey(guid, false);
        }