There should be an easy method to add/override the shadow of a RadWindow. Either via XAML attributes or code behind.
It would probably be good to allow the override of BlurRadius, Direction, and ShadowDepth.<telerik:RadWindow x:Class="MyRadWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
Header="Settings" WindowStartupLocation="CenterOwner" SizeToContent="True" ResizeMode="NoResize" MinWidth="500" MaxWidth="900" DropShadowOverride="True" DropShadowOverrideBlurRadius="10" DropShadowOverrideDirection"-90", DropShadowOverrideDepth="3" DropShadowOverrideColor="White">
<Grid>
<!-- UI code -->
</Grid>
</telerik:RadWindow>