The problem that I was having was with the picture quality of my comcast cable. The digital channels look great, but the problem is with the analog channels. When I run the signal into the cable box the quality of channels 1-100 look like crap. But if I plug the signal into the back of my TV, the picture is still a little grainy, but it is a lot better than what it looks going through the cable box.
I used to have directv until I moved about 3 months ago. The picture from directv looked great through, but ever since I got cable I haven't been happy with the picture quality.
Any advice or suggestions on how I could make he signal on the analog channels better would be greatly apreciated.

call comcast, they will come out and measure correct db signal to your house.

Are all of the analog channels very grainy or is it worst case at the lower channels?

Do you have any other inputs on your TV, if so try using composite or S video from the STB that may help some.

I had comcast at my house earlier this week and he said that my signal was good. I don't remember what he said my signal was, but he said that it was pretty good.

All the channels are equally grainy. I did try using composite video and the picture did improve some, but its still grainy. I don't know if its normal for the picture to be like that, I'm used to having directv. When comcast was at my house earlier this week he said the the picture was normal, but I don't understand why they would consider this normal.

The problem that I was having was with the picture quality of my comcast cable. The digital channels look great, but the problem is with the analog channels. When I run the signal into the cable box the quality of channels 1-100 look like crap. But if I plug the signal into the back of my TV, the picture is still a little grainy,but it is a lot better than what it looks going through the cable box. You might need a different "digital only" STB (no analog cable tuner). For channels 1-99, a digital-only STB would tune the simulcast QAM digital feed mapped to the appropriate 1-99 channel.

It will still be standard definition on channels 1-99, but you're likely to receive less video noise and snow than using the analog cable feed. Cable ops may have sacrificed S/N ratio on their relatively-inefficient analog video feeds in order to accommodate the growing bandwidth demands from Internet, digital voice, and proliferating digital video programming.

One would think that since I am paying for digital cable that my cable box would only pick up the digital version of the channels that are similcast in analog and digital.

One would think that since I am paying for digital cable that my cable box would only pick up the digital version of the channels that are similcast in analog and digital. Agree, that's why I think this is a problem with your STB grabbing the analog cable feed instead of the digital feed for channels 1-99 - unless there's an abnormal tech problem with your local Comcast digital transmissions for 1-99.

One would think that since I am paying for digital cable that my cable box would only pick up the digital version of the channels that are similcast in analog and digital.

Your box has the ability to pick up all channels.
Don't know if you will find a cable box that only demodulates the QAM carriers.
Just tune to the digital channels!

One would think that since I am paying for digital cable that my cable box would only pick up the digital version of the channels that are similcast in analog and digital.

You didn't by chance get a different tv at the same time this problem started happening did you? I wonder if in the area you live in they haven't switched the analog channels over to digital simulcast yet by chance. If you unplug the cable from the back of your box while on ch 2-99 does the picture go dark or does it pause on the screen? What model digital box do you have?