A Fraps question.....

I've just started using this & put my test flight to a DVD to ckeck how it looks.
I have a 20" wide screen monitor & playing the video & clicking the fullscreen button at lower right I see it in widescreen via Windows Media Player.
HOWEVER, when I play it from the DVD I burned it to, it will only play with 2 black bars at either side so the picture is squeezed into a square shape.
I want to see it in widesrceen & don't know how to do it....
I can't see from looking at WMP how to get rid of the bars....how do I do this, please?
I have a 20" wide screen monitor & playing the video & clicking the fullscreen button at lower right I see it in widescreen via Windows Media Player.
HOWEVER, when I play it from the DVD I burned it to, it will only play with 2 black bars at either side so the picture is squeezed into a square shape.
I want to see it in widesrceen & don't know how to do it....
I can't see from looking at WMP how to get rid of the bars....how do I do this, please?