Hi Gerard,
Welcome to the Microsoft Community. I am a Microsoft user just like you, and I hope you are well.
Please note: This is a user-to-user community forum. We are users just like you who help others. We are not employees of Microsoft.
If your microphone is stuck on mute despite multiple attempts to resolve the issue, there are a few steps you can take to troubleshoot and potentially fix the problem:
1. If your microphone has a physical mute button or switch, ensure that it's in the unmuted position. Sometimes, users accidentally press the mute button, which can mute the microphone.
2. Check your Teams settings to ensure that media permissions are turned on and that your microphone is selected as the default device:
Open Teams app - Click your picture on top right - Settings - Permissions - Media permission should be ON.
Also in Devices - Check for Audio Devices and Camera - By default, they are properly selected. If not, check them.
3. If the above doesn't work, Then follow the below instructions:
A) Press the Windows Key and X together and select Device Manager.
B) In the pop-up window, double-click the Audio inputs and outputs entry and find your mic device in the drop-down list.
C) Right-click your mic and then select Uninstall Device.
D). Restart your computer, the Windows reboot will install the Microphone driver automatically.
4. Try using a different microphone or headset to see if the issue is with your current device
I hope this helps! Let me know if you have any other questions.
Best Regards,
Umar Majeed