black ops fullscream error

hi.
i have one problem.
Always i star my black ops its have two side bars black on at left and another one on the right and in the middle i have the game. is like i wasn't playing in fullscream.
how can i fix???

Change resolution or aspect ratio.

i only can change to 1680:1050 and with that resolution i have 40 fps. aspect radio don't make nothing i already ry and didn't work

my problem was been fixed. don't need more help. thanks

my problem has been fixed. i change my screen to default settings