Audio system problem - Please HELP!

Lately, something on/in the audio system of my PC (an HP almost 9 years old that's still on Windows 7) appears to be failing.  I try to play a music CD in Windows Media Player (Version 12.0.7601.23930), but Track 1 fails to play, then Track 2 fails to play, and so do all the others.  Then I discover on YouTube that when I try to play a video, either I get a message saying that something is wrong with the audio such that my PC needs to be restarted or I get no audio whatsoever.   So, upon restarting my PC, everything becomes fine again, but the very first time this happened was in either late November or early December (2020).  Then the exact same thing occurred again just a few days later.  Now it just happened to me again (3rd time) less than 2 hours ago.

Very sorry (apologies) if this type of problem has already been addressed here many times before, but what could be my audio system's problem such that my PC needs to be restarted to fix it?  And what can be done about it?  Please help - I would very much appreciate anyone trying to help!