Open the Start Menu and click on the Settings cog
Click on Privacy
Choose Microphone from the list
Make sure Desktop apps have access to the microphone
Advanced Windows Troubleshooting
3) Check that Windows can see your microphone
This process is a little more advanced than the others, but it may prove useful if you're still having trouble
Right click on the Speaker icon on the right side of your taskbar
Click on "Open Sound settings"
Click on "Sound Control Panel" under "Related Settings"
In my screenshot, the Related Settings are on the right, however if your window is skinnier, you will have to scroll down to see the Related Settings
In the pop-up window, click once on the microphone that you are trying to use for Webex
If it has a green checkmark next to it, then Windows already sees it as the default device and it is the device Windows is trying to use
From this screen, you can see the level that the microphone is picking up. Try speaking into the microphone and watch the level meter to see if the level raises in response to your voice.
You may click on the Properties button to further investigate the problem
Click on the Listen tab
Click on the checkbox in the window to enable the Listen Feature. This will play whatever the microphone picks up through your speakers. Be wary of feedback loops!! Here you can hear for yourself what exactly the microphone is hearing. Be sure to uncheck this box as soon as you are done with this step!
The next tab you can check is "Levels". This tab contains a volume slider and a mute button for your microphone just like you have for your speakers. Try raising this if needed.