I looked at this for a few days with my cousin a couple of months ago, he has HD Dish and HD Cox cable and wanted to watch the HD channels on his mediapc w/ bluray. He currently sees all the standard channels but HD is just grey screen. We looked at 6-7 different cards and they all appear to sneakily say' over air HD' or in other words antenna based HD.
Speaking to a rep at Fry's electronics, he said there is no standard signaling for HD between vendors like it is with analog TV so you cant find a card to accommodate all of the different signaling being used. IDK if I believe that but it does kind of make sense. ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~