Quite by accident I stumbled upon Windows Media Center in Vista. I had no intention of using Vista as a media player as the machine I was building was solely intended as a World of Warcraft laptop replacement to service my evolving WoW requirements; played on my large wide screen monitor.
So within Vista I find Windows Media Center. What's this? It plays media, lots of media, all my media. It claims to play ATSC. I hook up a cheap, old USB ATSC tuner. Vista has drivers. Media Center recognizes it. It scans channels. It plays back all the over-the-air HD selections I receive. SOLD.