I have a custom htpc which I built. It has a core 2 quad processor, 4gb ram, 500gb hd running vista x64 bit. I have bought 2 different tuner cards to get this to work and just no luck. I have bought a ATI TV wonder 650 pcie and a Hauppauge WinTV-HVR 1600. Now I don't pay for cable but am able to receive about the first 20 stations of basic due to Comcast's filter they put on my line not cutting them off. When I attach the coax to my HDTV in my bedroom the television will pick up analog channels and HD local channels perfectly. Now when I hook the same coax to my HDTV Tuner cards for the HTPC I cannot receive 1 HD station. The analog channels will work fine. I have tried with both cards hooking the coax to the HD Tuners and the Analog but no HD. I split the cable and hooked it to both inputs the ATSC and Analog for both cards and Vista MC will recognize both tuners and the guide will display both but the HD still will not receive a signal. I don't even get HD OTA channels with an amplified antenna on my HTPC when my HD television will pick them up with the same antenna. Is this something with Vista Media Center and HD reception with my computer? I am at a loss because I have tried two different cards now. Just curious what might help? Thank you in advance.