public enum INTERNETFEATURELIST

         {

             FEATURE_OBJECT_CACHING = 0,

             FEATURE_ZONE_ELEVATION = 1,

             FEATURE_MIME_HANDLING = 2,

             FEATURE_MIME_SNIFFING = 3,

             FEATURE_WINDOW_RESTRICTIONS = 4,

             FEATURE_WEBOC_POPUPMANAGEMENT = 5,

             FEATURE_BEHAVIORS = 6,

             FEATURE_DISABLE_MK_PROTOCOL = 7,

             FEATURE_LOCALMACHINE_LOCKDOWN = 8,

             FEATURE_SECURITYBAND = 9,

             FEATURE_RESTRICT_ACTIVEXINSTALL = 10,

             FEATURE_VALIDATE_NAVIGATE_URL = 11,

             FEATURE_RESTRICT_FILEDOWNLOAD = 12,

             FEATURE_ADDON_MANAGEMENT = 13,

             FEATURE_PROTOCOL_LOCKDOWN = 14,

             FEATURE_HTTP_USERNAME_PASSWORD_DISABLE = 15,

             FEATURE_SAFE_BINDTOOBJECT = 16,

             FEATURE_UNC_SAVEDFILECHECK = 17,

             FEATURE_GET_URL_DOM_FILEPATH_UNENCODED = 18,

             FEATURE_TABBED_BROWSING = 19,

             FEATURE_SSLUX = 20,

             FEATURE_DISABLE_NAVIGATION_SOUNDS = 21,

             FEATURE_DISABLE_LEGACY_COMPRESSION = 22,

             FEATURE_FORCE_ADDR_AND_STATUS = 23,

             FEATURE_XMLHTTP = 24,

             FEATURE_DISABLE_TELNET_PROTOCOL = 25,

             FEATURE_FEEDS = 26,

             FEATURE_BLOCK_INPUT_PROMPTS = 27,

             FEATURE_ENTRY_COUNT = 28

         }

        private const int SET_FEATURE_ON_THREAD = 0x00000001;

         private const int SET_FEATURE_ON_PROCESS = 0x00000002;

         private const int SET_FEATURE_IN_REGISTRY = 0x00000004;

         private const int SET_FEATURE_ON_THREAD_LOCALMACHINE = 0x00000008;

         private const int SET_FEATURE_ON_THREAD_INTRANET = 0x00000010;

         private const int SET_FEATURE_ON_THREAD_TRUSTED = 0x00000020;

         private const int SET_FEATURE_ON_THREAD_INTERNET = 0x00000040;

         private const int SET_FEATURE_ON_THREAD_RESTRICTED = 0x00000080;

        [DllImport("urlmon.dll")]

         [PreserveSig]

         [return: MarshalAs(UnmanagedType.Error)]

         static extern int CoInternetSetFeatureEnabled(

              INTERNETFEATURELIST FeatureEntry,

              [MarshalAs(UnmanagedType.U4)] int dwFlags,

              bool fEnable);

        [DllImport("winmm.dll")]

        public static extern int waveOutGetVolume(IntPtr h, out uint dwVolume);

        [DllImport("winmm.dll")]

        public static extern int waveOutSetVolume(IntPtr h, uint dwVolume);

        private void Form1_Load(object sender, EventArgs e)

        {

            try

            {

               // waveOutSetVolume(0, 0xFFFF); //禁止当前进程发出声音

                CoInternetSetFeatureEnabled(INTERNETFEATURELIST.FEATURE_DISABLE_NAVIGATION_SOUNDS, SET_FEATURE_ON_PROCESS, true);

                uint _savedVolume;

                waveOutGetVolume(IntPtr.Zero, out _savedVolume);

                this.FormClosing += delegate

                {

                    // restore the volume upon exit

                    waveOutSetVolume(IntPtr.Zero, _savedVolume);

                };

                // mute

                waveOutSetVolume(IntPtr.Zero, 0);

            }

            catch (Exception ex)

            {

                Console.WriteLine(ex.Message);

            }

}

}