[c#] App.Config change value

For a .NET 4.0 console application, none of these worked for me. So I modified Kevn Aenmey's answer as below and it worked:

private static void UpdateSetting(string key, string value)
{
    Configuration configuration = ConfigurationManager.
        OpenExeConfiguration(Assembly.GetExecutingAssembly().Location);
    configuration.AppSettings.Settings[key].Value = value;
    configuration.Save();

    ConfigurationManager.RefreshSection("appSettings");
}

Only the first line is different, constructed upon the actual executing assembly.