To fix, just click them, click Set Default, then click OK and test whether you have sound.
If your Speakers are NOT already set as the default, this is doubtless your problem. This indicates that your speakers are the default playback device.
Check if your speaker or headphone has been muted by accident. If the audio device has been muted, you won’t hear sound from it.
If they work in another computer, the problem is probably caused by the cable. You can plug them to in another computer and see if they work in another computer. If you don’t hear sound from your external audio devices, like speakers and headphones, you can check if their cable is broken. Just start at the top of the list and work your way down. You don’t necessarily have to try them all. More importantly, it’s usually a pretty easy problem to resolve. So if you’re experiencing this problem, rest assured, you’re not alone. Particularly immediately after upgrading from a previous version of Windows.
One of the most common problems with Windows 10 is no sound.