Question

I am new to programming. I’ve been given a virtual conferencing site. Now i need to modify the site.

While the user logins into the conferencing site,it must detect whether his system has a particular software installed in his system(that software is used for making video calls.It uses ActiveX objects).

Which is the best method to detect the presence of the installed software in the system? (Frankly speaking i don’t even know which language best serves the purpose)

Answer 1

    public static bool IsApplictionInstalled(string p_name)
{
    string keyName;

    // search in: CurrentUser
    keyName = @"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall";
    if (ExistsInSubKey(Registry.CurrentUser, keyName, "DisplayName", p_name) == true)
    {
        return true;
    }

    // search in: LocalMachine_32
    keyName = @"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall";
    if (ExistsInSubKey(Registry.LocalMachine, keyName, "DisplayName", p_name) == true)
    {
        return true;
    }

    // search in: LocalMachine_64
    keyName = @"SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall";
    if (ExistsInSubKey(Registry.LocalMachine, keyName, "DisplayName", p_name) == true)
    {
        return true;
    }

    return false;
}

private static bool ExistsInSubKey(RegistryKey p_root, string p_subKeyName, string p_attributeName, string p_name)
{
    RegistryKey subkey;
    string displayName;

    using (RegistryKey key = p_root.OpenSubKey(p_subKeyName))
    {
        if (key != null)
        {
            foreach (string kn in key.GetSubKeyNames())
            {
                using (subkey = key.OpenSubKey(kn))
                {
                    displayName = subkey.GetValue(p_attributeName) as string;
                    if (p_name.Equals(displayName, StringComparison.OrdinalIgnoreCase) == true)
                    {
                        return true;
                    }
                }
            }
        }
    }
    return false;
}