For no good reason other than being a curious geek I upgraded three perfectly good Windows 7 64 bit machines to windows 8, and put Media Center on all three while the price was cheap. Two of the computers are fine, one has a strange Media Center audio problem. It is a home-built low power HTPC that wasn't running much else besides Windows Media Center. It is connected to a TV via an HDMI cable. I leave the PC with media center running most of the time.
Most of the time (but not always, I can't pin down exactly how to reproduce the problem 100% of the time), when after a day or so of the HTPC sitting I switch the TV from TV mode to using the HDMI input connected to the HTPC, the sound doesn't work. One of the following two workarounds always turns the sound back on: 1. I "unmaximize" (is there a word for that???) Windows Media Center, and the sound (may) come on, then I re-maximize media center and all is well. 2. If 1. doesn't work, which has happened more lately, I exit Windows Media Center and restart it, and the sound comes back on. Not bad workarounds, but it gets very tiresome after a while to do this nearly every time we use the HTPC. I am about ready to restore my pre-Windows-8 image backup, and hope I can use my Windows/Media Center serials later on another machine, but I thought I would ask the gurus here first.
More background. The HTPC uses an ASRock H67M-ITX motherboard (terrific, the HTPC only uses 22 watts or so). There is an up-to-date Realtek High Definition Audio driver on board, but apparently it is not used, because the HDMI output uses an "Intel Display Audio" driver with a 2010 date. Thinking I might have an audio driver issue, I have searched high and wide for an Intel Display Audio driver update but not found one.
Other things I have done are turn off the screen saver (though a screen save does come on from somewhere displaying my photos - maybe this is related to the problem?). I have updated every possible driver I could find, including the Realtek. I briefly tried connecting the HTPC to the TV using VGA, but the video results were bad, whereas the HDMI connection did great. If the VGA had worked, I would have connected the sound via conventional sound cables rather than HDMI.
So this is more a puzzle than a problem because I have an effective but annoying workaround, and I can "cure" the problem by reverting to Windows 7 and lose nothing except false pride in my self-identity as a geek :-)
(I am also considering abandoning Windows Media Center for a free Media Center alternative, but that's another topic altogether!)
I would appreciate any suggestions from the lounge gurus!!!