No Audio Streaming to PC on HDMI

I recently purchased Roku 4k express model ##391X4 and I watch on my desktop computer via HDMI. Everything had been working fine, but then it stopped playing any sound. I am viewing the Roku on VideoPad by NCH software. Audio worked for about two weeks, but tonight it went out.  What settings do I accesson a pC computer to make sure the HDMI cable has audio.