This is part of the video itself, and not a problem with the hardware. The reasoning is that your TV doesn't have the same dimensions as the original film, so the bars make the video smaller, using the full width to show the whole shot.
Often, with DVDs as well, you can select a full-frame video that makes use of Pan&Scan or another technology that was used to modify the video before placing it on the disc.
In addition, some TVs can "see" this black area and accommodate by stretching the video vertically to fill the screen. With this, everything will appear stretched and look odd. I find it's best to eithe renjoy the full screen with the black bars, or to watch an alternative full-frame version, although you do miss out on a lot of the film.