HowTo Disable WebBrowser 'Click Sound' in your app only

using System;
using Microsoft.Win32;

namespace HowTo
{
    class WebClickSound
    {
        /// <summary>
        /// Enables or disables the web browser navigating click sound.
        /// </summary>
        public static bool Enabled
        {
            get
            {
                RegistryKey key = Registry.CurrentUser.OpenSubKey(@"AppEventsSchemesAppsExplorerNavigating.Current");
                string keyValue = (string)key.GetValue(null);
                return String.IsNullOrEmpty(keyValue) == false && keyValue != """";
            }
            set
            {
                string keyValue;

                if (value)
                {
                    keyValue = "%SystemRoot%\Media\";
                    if (Environment.OSVersion.Version.Major == 5 && Environment.OSVersion.Version.Minor > 0)
                    {
                        // XP
                        keyValue += "Windows XP Start.wav";
                    }
                    else if (Environment.OSVersion.Version.Major == 6)
                    {
                        // Vista
                        keyValue += "Windows Navigation Start.wav";
                    }
                    else
                    {
                        // Don't know the file name so I won't be able to re-enable it
                        return;
                    }
                }
                else
                {
                    keyValue = """";
                }

                // Open and set the key that points to the file
                RegistryKey key = Registry.CurrentUser.OpenSubKey(@"AppEventsSchemesAppsExplorerNavigating.Current", true);
                key.SetValue(null, keyValue,  RegistryValueKind.ExpandString);
                isEnabled = value;
            }
        }
    }
}

private void Form1_Activated(object sender, EventArgs e)
{
    // Disable the sound when the program has focus
    WebClickSound.Enabled = false;
}


private void Form1_Deactivate(object sender, EventArgs e)
{
    // Enable the sound when the program is out of focus
    WebClickSound.Enabled = true;
}


private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    // Enable the sound on app exit
    WebClickSound.Enabled = true;
}

webBrowser1.DocumentText = "<h1>Hello, world!</h1>";

webBrowser1.Document.OpenNew(true);
webBrowser1.Document.Write("<h1>Hello, world!</h1>");

const int FEATURE_DISABLE_NAVIGATION_SOUNDS = 21;
    const int SET_FEATURE_ON_PROCESS = 0x00000002;

    [DllImport("urlmon.dll")]
    [PreserveSig]
    [return: MarshalAs(UnmanagedType.Error)]
    static extern int CoInternetSetFeatureEnabled(
        int FeatureEntry,
        [MarshalAs(UnmanagedType.U4)] int dwFlags,
        bool fEnable);

    static void DisableClickSounds()
    {
        CoInternetSetFeatureEnabled(
            FEATURE_DISABLE_NAVIGATION_SOUNDS,
            SET_FEATURE_ON_PROCESS,
            true);
    }

// backup value
RegistryKey key = Registry.CurrentUser.OpenSubKey(@"AppEventsSchemesAppsExplorerNavigating.Current");
string BACKUP_keyValue = (string)key.GetValue(null);

// write nothing
key = Registry.CurrentUser.OpenSubKey(@"AppEventsSchemesAppsExplorerNavigating.Current", true);
key.SetValue(null, "",  RegistryValueKind.ExpandString);

// do navigation ...

// write backup key
RegistryKey key = Registry.CurrentUser.OpenSubKey(@"AppEventsSchemesAppsExplorerNavigating.Current", true);
key.SetValue(null, BACKUP_keyValue,  RegistryValueKind.ExpandString);