You can follow the same operation to update the audio drivers of your computer default sound card. hi, so this has happened before, sound in windows is not working, in device manager the sound card shows as 'Realtek(R) Audio' but windows sound service doesnt start and on taskbar speaker icon is stuck like its muted According to threads Ive found on reddit and forums it should be fixable by right clicking the Realtek(R) audio - properties - driver - update driver - let me pick from a list.
After this, the Stereo Mix device should appear in the list of recording devices.
Check how to make Realtek HD Audio Stereo Mix feature visible. If you don’t see Stereo Mix under Recording tab in Sound window, it might be hidden in your sound card. Read More Fix Realtek Stereo Mix Not Showing or Missing in Windows 10 New version of High Definition Audio drivers for sound card from the company Realtek, drivers are designed for operating systems Windows XP, Vista.