Have you looked in the sound portion of Windows Control Panel? If devices are missing from there, you won't see them listed in MC either; MC can only show the devices Windows presents to it.
And if the devices are missing in the Windows control panel, that's not something MC can make happen. That would be a windows or driver issue.
What exactly are you expecting to see? You mention HDMI on the video card, but what is it connected to? If the video card is connected to a monitor that does not have audio capability, I don't think Windows will list it as an audio device. So if the Denon is connected to the Intel graphics on the motherboard, what else specific are you expecting to see? You mention other devices being missing, but didn't enumerate what they were.
Could it also be possible some Windows updates were installed, with or without your consent? A lot of nonsense occurs with new Windows updates, especially lately. Can you still print?