you'll need an HD tuner card, to start with. shop around online. beyond that, you need a cable to connect your tuner to the receiver. that's about it for the biggies.
Thanks for the suggestions. I think I may be making it harder than it actually is. I'm not computer literate, but I'm worry my graphics card may not be up to par. I have been doing some internet research. It looks like HD for PC is only available over the air and not through the cable. Is there any way around this. I would actually like to record hd to pc from my cable. When setting up the timer to record a show do I need to connect to the internet to view a tv program schedule or can I simply set the time and channel?