gistfile1.cs

IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;

        public About()
        {
            InitializeComponent();
            InitializeSettings();
        }

        private void InitializeSettings()
        {
            if (settings.Contains("dynamicOn"))
            {
                DynamicCheck.IsChecked = (bool)settings["dynamicOn"];
            }
            else settings.Add("dynamicOn", true);
            settings.Save();
        }

        private void DynamicCheck_Unchecked(object sender, RoutedEventArgs e)
        {
            settings["dynamicOn"] = false;
            settings.Save();
        }

        private void DynamicCheck_Checked_1(object sender, RoutedEventHandler e)
        {
            settings["dynamicOn"] = true;
            MessageBox.Show("The background agent has now started. Your wallpaper should update every 2 minutes or so.");
            settings.Save();
        }