>Hi,
>
>I have a window with a ScrollViewer. The ScrollViewer has a TabControl with TabItems. Each TabItem has a Grid with Two Columns. The main content is in the Left Column. In the Right Column there are expanders with aditional Information that makes the VerticalScrollBar appear. When I scroll I want the left side of the window to be freezed. Is it posible?

Why not just wrap the Expanders themselves in a ScrollViewer ?