My PC has developed a problem with sound output, I can only select ‘stereo’ whereas before I could select anything up to 7.1 surround. My setup is as follows: PC, Asus ROG Strix Z370-H Motherboard, Windows 10 Home 64-bit, GTX1080ti through high-speed HDMI cable to Pioneer 4K capable AV Receiver connected to 5.1 speakers, AV receiver is connected though high-speed HDMI to Panasonic 4K TV. Up until last night all was working well, but on starting a game I noticed there was no sound, so upon checking sound setup in windows for some reason I am now only able to select ‘stereo’ instead of 5.1 as I had before. After re-installing the nvidia drivers a couple of times without fixing the problem, I decided to do a repair of windows. Unfortunately I didn’t have restore points turned on so couldn’t roll back a few days. Even after doing the repair to windows and reinstalling the nvidia drivers, chipset drivers etc, I can still only select stereo, very frustrating. I don’t know what else I can do to fix it, I spent a lot on this set up and want to get back to the full surround sound experience, not crummy stereo, it’s not even 2.1. Please help!!