How to change FontFamily of Window form?

I cannot change fontfamily or fontstyle for title of Window Form even though I have already set these properties.The default fontfamily is MS UI Gothic and I want change to meiryo.At XML file, It seems ok but It doesnt have any changes at runtime.

 <Window x:开发者_JAVA技巧Class="TestFont.Window1"
   xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
   xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
   Title="Window1" Height="130" Width="369" FontFamily="meiryo"  FontStyle="Italic">
</Window>

The window caption is part of the non-client area of the window is not really rendered by WPF. The only way you can change that font is by modifying your display properties (a Windows-wide setting).

You can not change the look of the title text. It's decided by theme used, personal settings etc. so it's different on every computer according to the users liking.