Built-in microphone stops working on computer

Because external microphones work while the built-in microphone is absent from every app, app permissions are unlikely to be the whole problem; Windows may not be enumerating the internal audio device. In Settings > System > Sound > Input, select All sound devices and check whether the internal microphone is disabled. Run the Input devices troubleshooter. In Device Manager, choose View > Show hidden devices, then inspect Audio inputs and outputs and Sound, video and game controllers. Enable the internal device if disabled; otherwise uninstall the microphone and audio-controller entries, restart, and scan for hardware changes. Install the computer manufacturer’s audio, chipset, and BIOS updates. Check any microphone-mute key and the firmware audio setting. If the microphone never appears in Device Manager but external microphones do, test with the manufacturer’s preboot diagnostics. A failure there confirms hardware or cabling rather than Windows, and the built-in microphone assembly will need service.