void task_Completed(object sender, PhotoResult e) { if (e.ChosenPhoto == null) { return; } string uploadLocation = "/shared/transfers/Image" + DateTime.Now.Millisecond + ".jpg"; BackgroundWorker worker = new BackgroundWorker(); worker.DoWork += (o, args) => { using (IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication()) { using (IsolatedStorageFileStream stream = store.CreateFile(uploadLocation)) { byte[] buffer = new byte[1 << 10]; int bytesRead; while ((bytesRead = e.ChosenPhoto.Read(buffer, 0, buffer.Length)) > 0) { stream.Write(buffer, 0, bytesRead); } } } }; worker.RunWorkerCompleted += (o, args) => { LiveConnectClient uploadClient = new LiveConnectClient(App.Session); uploadClient.BackgroundUploadCompleted += new EventHandler <LiveOperationCompletedEventArgs>(uploadClient_BackgroundUploadCompleted); string userState = "myUserState"; // arbitrary string to identify the request. uploadClient.BackgroundUpload(SelectedAlbum.ID, new Uri(uploadLocation, UriKind.RelativeOrAbsolute), userState); }; worker.RunWorkerAsync(); }