But they won't playback a HD-DVD.
Although I should qualify that statement. They are all capable of playing the video content of an HD-DVD, but none of them will handle the copy protection, interactive features, or menu systems. If you want to play them on windows you need to buy software to do it. This will either be an actual player, or something else that will let these access the video content of the disk. the second option I'm not going to go into on these forums as it is has a very dubious legal background.