bill - 12:53 am on Jul 25, 2005 (gmt 0)
You would have to change the View settings to remove this panel.
Tools ¦ Folder Options... ¦ General (tab)
On the General tab you would select "Use Windows classic folders" and that should remove the entire pane where .avi previews show up. This also removes any other common task previews that might show up in this panel.