I receive DW programs via satellite or via cable; even though I have a 16:9 flat screen tv, the broadcast in 16:9 format has black bars surrounding

Cable:
This type of picture is caused by an incoming picture in letterbox format being shown on a 16:9 screen which is in 4:3 mode. Letterboxing is the cause of the black bars at the top and bottom of the picture and the 4:3 (pillarbox) mode is responsible for the black bars at the side of the picture
Cable providers often letterbox programs received in 16:9 widescreen format. If your appliance does not have an automatic format adjustment facility, the display format needs to be altered using the flat screen TV’s navigation menu
Unfortunately, there is no standardization for flat screen menu navigation. Please refer to the user’s manual for detailed menu navigation.

Satellite:
This is caused by an incoming picture in letterbox format being shown on a 16:9 screen which is in 4:3 mode. Letterboxing is the cause of the black bars at the top and bottom of the picture and the 4:3 (pillarbox) mode is responsible for the black bars at the side of the picture.

A number of set-top boxes have the facility to alter the screen format of the connected TV appliance using the remote control and the navigation menu. It is probable that the screen format of the connected TV appliance has been incorrectly set to 4:3 format instead of a 16:9 format.
If the set-top box receives a program in 16:9 widescreen format, it automatically produces a picture signal in letterbox format; letterboxing is the optimal viewing format for a 16:9 widescreen picture on a TV set with a 4:3 screen.
Use the navigation of your set-top box to change the format of the connected TV appliance to 16:9 format.
Unfortunately, there is no standardization for menu navigation. Please refer to the user’s manual for detailed menu navigation.