Need help with display settings

[westofhwy5]

I am new to this forum and I hope I am in the right place but I need some advice on configuring my PC to display through my Zenith HDTV rear projection LCD TV. My computer is a new HP, great video card, capable of resolutions upwards of 2k X something or other. I am using a DVI cable from PC to TV. The TV is a few years old at least, it is a Zenith 44", model #E44W46LCD, it is 1080i as you might have guessed and it does not have the tuner built in.

Heres the problem:

I cant get resolutions higher than 1024 x 768 !! Is this a limitation of my TV? I know it cant be a limitation of the video card. IF it is the TV, which I kinda know it is, is there any way around it? Someone mentioned a HDTV tuner but they didnt offer much in the way of what to get and how it would help me etc etc. Any help is appreciated, this one might be easy for you guys, please help!!!

Thanks
-westofhwy5