Advertisements I have decided to not suffer another new TV season with my crappy Comcast HD DVR. So I have jumped back into the fray after 1.5 years of Tivo-less hell. I bought a new Tivo HD. It's on its way. I suppose I will call Comcast and set up my cablecard appointment when I know the new Tivo will be here. My question is: When do I sign up for my Tivo service? Before Comcast gets here, during, or after? I would think I'd need to register my new Tivo and pay for my service plan before Comcast gets here.