screen resolution

i have i lg 42" hdtv and i have just bought a packard bell computer which uses windows 7, i plugged a rgb cable in and an audio cable they both worked fine the screen fit perfect, until i plugged a hd cable in, my resolution is 1920 x 1080 (recommended), however this does not fit my tv it is to big, although when i try to go 1680 x 1050 which is the one below it simply is to small. so i have no idea what to do ????

I've always had much better luck using HDMI cables for large TVs. I know for my 42" Vizio, once I set the resolution, I had to also adjust the positioning and size in the TV's settings.

On a side note...Packard Bell still makes computers? I thought they went out of business over a decade ago.