You need to enable Dolby Digital and DTS from your motherboards sound software. Then it will work.
However upon further inspection.
Your motherboards sound card doesn't support DTS or Dolby live.
You have two options.
1. Connect ur HDMI out on ur gpu to the receiver HDMI in on game Blu-ray tv or whatever. Then your receiver will popup in windows control panel under sound and select it as the output for the sound and hit configure and it will bring up all the options 5.1 7.1 Atmos etc. You don't need anything other than the Nvidia gpu drivers installed with the hd audio.
2. Buy a sound card like a sound blaster z that has Dolby and use the optical out to connect to the receiver.
I'm using a receiver with a 9.2 setup and it works perfectly via HDMI or optical I have both hooked up.
Using a sound blaster and HDMI out from my gpu. I can switch between the two as well.