No Background Worker
<UserControl x:Class='SilverlightApplication3.MainPage' xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' xmlns:d='http://schemas.microsoft.com/expression/blend/2008' xmlns:mc='http://schemas.openxmlformats.org/markup-compatibility/2006' mc:Ignorable='d' d:DesignWidth='640' d:DesignHeight='480'> <Grid x:Name="LayoutRoot" Background="White"> <Grid.ColumnDefinitions> <ColumnDefinition /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition /> <RowDefinition /> </Grid.RowDefinitions> <TextBox x:Name="txtEntry" Width="200" Height="20" Grid.Column="0" Grid.Row="0" /> <Button x:Name="btnStartTask" Width="100" Height="20" Grid.Column="0" Grid.Row="1" Content="Start Task" Click="btnStartTask_Click" /> </Grid> </UserControl> //File: Page.xaml.cs using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Animation; using System.Windows.Shapes; namespace SilverlightApplication3 { public partial class MainPage : UserControl { public MainPage() { InitializeComponent(); } private void btnStartTask_Click(object sender, RoutedEventArgs e) { System.Threading.Thread.Sleep(2000); } } }