After installing Windows 10 on my production device (with a Windows 8.1 Hyper-V VM as back-up, of course), I had an issue with the HDMI Audio of my Dell Latitude E6540 notebook. I found some topics online about setting the default format of the Audio device, such as sample rate and bit depth, but that doesn’t work for me.
I had to reconfigure my Receiver + 5.1 Audio as “5.1 Surround”, instead of the default “Stereo”. You can find this option when you right click the speaker-icon in your taskbar and then click “Sound”. The “Stereo” option worked for me before within Windows 8.1, but with Windows 10, I had to reconfigure this setting. After Windows Update installed the latest Intel Display Audio driver (126.96.36.19979), I had to configure the “5.1 Surround” again.
Let me know if you had these issues too!