Add-Type -AssemblyName PresentationFramework [XML]$form = @" <Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" Title="MainWindow" Height="450" Width="800"> <Grid> </Grid> </Window> "@ $NR = (New-Object System.Xml.XmlNodeReader $form) $window = [Windows.Markup.XamlReader]::Load($NR) $window.ShowDialog()