the following code is to change the background for WPF button
<button content="Button" height="23" horizontalalignment="Left" margin="400,111,0,0" name="button1" verticalalignment="Top" width="75">
<Button.Background>
<imagebrush imagesource="/your Project;component/Images/BackGround.PNG" />
</Button.Background>
</Button></button>
Hope this will help
<Border BorderThickness="5">
<Border.BorderBrush>
<ImageBrush ImageSource="/WCF_TEST;component/Images/Tulips.jpg"/>
</Border.BorderBrush>
<Image x:Name="ImageControl" Source="/WCF_TEST;component/Images/Hydrangeas.jpg"/>
</Border>