First, I couldn't find a thread where this would fit, so if this needs to be moved please do so.

Second, my problem, actually my parents problem, is that they have a Explorer 4240 HDC from TWC. My mother picked up the boxes from the local office so there was no tech installing the boxes. The problem I believe comes from the box.

My step father bought a brand new Samsung 46" that can go up to 1080p. I know the HD cable is only broadcast in 1080i. Now the box shows that it is sending a 1080i signal. But whenever we go to watch ESPN HD on his TV the letterbox does not go away (does not fill the screen). You can Zoom in to fill the screen but it looks like garbage.

I recently purchased Digital Cable with HD through Grande Comm. My box is a 4250 HDC so there is not much difference. When the Grande tech set my box up, he pressed two buttons at the same time and a menu came up asking the what resolution. Once he chose 1080i, my Sony 52" had letterbox whatsoever and filled the screen in pure HD when watching ESPN HD.

Any tips on what I can do to help my parents?

I would call TWC and talk to a tec and they will walk you thru the set up,thats what it sounds like it needs.