If you see a red X on the speaker icon in the notification area and move your mouse over the icon, you see a message The audio service does not work on your Windows 10/8/7 PC, so here are some things you need to look at.
1] Check Windows Services status
Start services.msc to open Windows Services Manager. Scroll down to Windows Audio Service and double-click to open its properties. This service manages audio for Windows programs. If this service is stopped, the audio devices and effects will not function properly. If this service is disabled, not all services that explicitly depend on it are started