Maintain WPF Window Size across different resolution monitors

Good Day 

I am building a Kinect Applications. So i am using WPF on my laptop with the resolution of 

1920 * 1080

so everything looks great and last night , i wanted to test it on my Samsung HD TV 42 inch Plasma and my Buttons went missing. 

So my TV resolution is 1024 x 768(NATIVE)

so i reduced my resolution to  1024 x 768 on my laptop and i experienced the same thing my TV was experiencing. 

I need an Advice to adjust my apps layout to accommodate all resolutions from 

1024 x 768(NATIVE) and higher resolution. 

Here is an example of a Page that i have , so basically i am using navigation service i have one window that hold the frame and i make it full-screen and others are just pages. 

<Page x:Class="SchoolPlay1.MainMenu"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
        xmlns:local="clr-namespace:Microsoft.Samples.Kinect.ControlsBasics"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"  
        xmlns:k="http://schemas.microsoft.com/kinect/2013" 
        xmlns:tk="clr-namespace:Microsoft.Kinect.Toolkit;assembly=Microsoft.Kinect.Toolkit"  
     KeepAlive="false"
       Height="1008.94" Width="2086.684"
	Title="MainMenu"><Page.Background><ImageBrush ImageSource="/SchoolPlay1;component/Background/Background_Math.png" /></Page.Background><Grid Canvas.Top="-16" x:Name="LayoutRoot" Width="1636"><Grid Grid.Row="0"  Margin="10,0,0,19.6"> <k:KinectUserViewer k:KinectRegion.KinectRegion="{Binding ElementName=kinectRegion}" Height="100" HorizontalAlignment="Center" VerticalAlignment="Top" /></Grid><k:KinectRegion x:Name="kinectRegion" Margin="-226,10,-224,6.8" HorizontalAlignment="Right" Width="2086"><Grid x:Name="kinectRegionGrid" Margin="10,20,160,19.8"><Grid.RowDefinitions><RowDefinition Height="*" /><RowDefinition Height="170" /></Grid.RowDefinitions><k:KinectTileButton   x:Name="btnAlphabets"     Canvas.Left="386"  Width="Auto" Height="Auto" Canvas.Top="98"   Click="btnAlphabets_Click" Background="{x:Null}" BorderBrush="{x:Null}" Margin="29,53,1521.4,153.4"><Image Source="/SchoolPlay1;component/MainMenuImages/Final_Alphabet.png" Height="426" Width="342"  /></k:KinectTileButton><k:KinectTileButton  x:Name="btnMath" Width="Auto" Height="Auto"  Canvas.Top="98"  Click="btnMath_Click" Canvas.Left="10" Background="{x:Null}" BorderBrush="{x:Null}" Margin="400,53,1137.4,153.4"><Image Source="MainMenuImages/MathMenu.png" Height="429" Width="352"  /></k:KinectTileButton><k:KinectTileButton   x:Name="btnFruitAndVeg"     Canvas.Left="702"   Canvas.Top="117" Width="Auto" Height="Auto"  Click="btnFruitAndVeg_Click_1" Background="{x:Null}" BorderBrush="{x:Null}" Margin="810,109,783.4,153.4"><Image Source="MainMenuImages/FruitAndVegMenu.png" Height="386" Width="302"  /></k:KinectTileButton><k:KinectTileButton   x:Name="btnMiscellaneouss"      Width="Auto" Height="Auto"   Background="{x:Null}" BorderBrush="{x:Null}" Margin="1161,141,431.4,198.4" Click="btnMiscellaneouss_Click" IsEnabled="False"  ><Image Source="MainMenuImages/Miscellaneous_Menu.png" Height="526" Width="302"  /></k:KinectTileButton><k:KinectTileButton    Background="{x:Null}" BorderBrush="{x:Null}"  x:Name="btnBack"      Click="btnBack_Click"   Height="Auto" Width="Auto" Margin="-212,257,211.4,-88" Grid.RowSpan="2"  ><Image Source="NavigationButtons/Back.png" Height="200" Width="500"  /></k:KinectTileButton></Grid></k:KinectRegion><tk:KinectSensorChooserUI HorizontalAlignment="Center" VerticalAlignment="Top" x:Name="sensorChooserUi" Margin="461,10,538,0" /></Grid></Page>

Thanks 

Vuyiswa Maseko