If you have a newer widescreen TV, you may find that the sides have black boxes on your screen.  The boxes can be removed from SD channels by widening the picture via your TV remote (instructions vary by TV).  The black boxes that appear on LOCAL channels periodically are NOT removable.  Those black boxes are being placed their by the content provider (CBS, ABC, etc.).  This link better explains the aspect ratio of TV’s.

Posted in: VIDEO FAQ, Cable Transition FAQ