void UpdaterWorker_DoWork(object sender, DoWorkEventArgs e) { Updater updater = new Updater("http://update.better-explorer.com/update.xml", 5); if (updater.LoadUpdateFile()){ Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Normal, (Action)(() => { UpdateWizard updateWizzard = new UpdateWizard(updater); updateWizzard.ShowDialog(this.GetWin32Window()); })); } }