(Do you have the correct driver? Are the audio services running? )
If any changes were made in msconfig this could have caused the problem. Revert the changes, and test. If the sound works, try and determine which change caused the problem, and change the others back to their changed condition.
If this option is available to you, doing a system restore to an earlier point may help.
First try start the Windows Audio service by the steps:
(Same as clicking on the Start Button, typing "services.msc" in the Search Bar and pressing Enter to start Services.)
This is the "Services" window, it lists all the system services. In the right pane look for "Windows Audio" (NOT "Windows Audio Endpoint Builder"). To find this quickly on could click on any service, then press the letter "W" on your keyboard.
Right click on the "Windows Audio" service and choose "Properties"
First just press stop, wait for it to stop, then press start. If this does not fix the problem, continue.
Click on the "Dependencies" tab.
You will see the "This service depends on the following system components" box, it displays 3 services (Remote Procedure Call (RPC), Multimedia Class Scheduler, and Windows Audio Endpoint Builder). Beside each service there is a "+" icon, click on it to expand the list. The 2nd service will have 2 child services; the 3rd service will have 1 child service.
Now make sure that all the 6 services (3 main, 3 child) have the "Started" status in the "Services" window you opened.
Most probably you will find one of those services is not running, start all of them (?), and then try to start the "Window Audio" service from the "General" tab.
In the tab "General ", make sure the "Startup Type" is "Automatic".
Click the button "Start" under "Service Status" to start this service (if it is not greyed-out).
Make sure the startup type is AUTOMATIC then click the start button then ok to close the window.
Reboot your computer.
1-Go to "services.msc".
2-Scroll to Windows Audio and double click it.
3-Make sure startup type is automatic.
4-Stop the service
5-Start the service.
Make sure that Windows Audio is checked in msconfig.exe
Also, you can run audio Troubleshooter by going to:
Start -> Control Panel -> Troubleshooting -> Troubleshooting audio playback
Follow the wizard to complete the troubleshoot.
Do a Clean Boot. If the issue disappears in the Clean Boot environment, we can use a 50/50 approach to quickly narrow down which entry is causing the issue. I do not know anything about this, so Google it.
Missing Icons (sound, battery) from the task bar: