Windows 7: Tv tuner setup problems

I recently bought an HD tv tuner so I can watch and record TV on my computer. I initially set it up with a splitter directly from my cable wall outlet, and it got a beautiful HD picture, but only detected the basic cable channels (networks). I wanted to get all the cable channels that I get through my set top box (are these considered "encrypted?"). I called Comcast (cable company) help and they were basically NO help. (The service agent seemed to know nothing about tuners for computer, and was basically reading the FAQs that I had already read.) Anyway, she said that if I routed the signal through my set top box into the tuner, I should receive all my cable channels.

SO, I had to get a new cable box with both an HDMI output (for my TV) and a coaxial output (to connect to the tuner). Now, Windows Media Center is detecting NO CHANNELS. It keeps saying it does not detect an "IR Blaster." I know that is part of a WMC remote, which I do not want to use. Is there any way to set up the TV signal without the IR Blaster?

I attempted to set up the TV signal by saying I was NOT using a set top box, and it detected no channels in the scan.

Is there any way to get all my cable channels in WMC, or am I only going to be able to watch the networks? Do I need another type of tuner? I am using AVerTV Hybrid Volar MAX. It was a great price and got great reviews, and I guess it worked great for me as long as I only wanted to watch the standard networks. But I really want to watch History, Discovery, Animal Planet, etc.

Should I use another program besides Windows Media Center?