Ensuring your microphone works properly is essential for voice communication on your computer. Use the Sound settings dialog on your Windows 8 and 8.1 devices to test both internal and external microphones.
Testing a Microphone
Swipe your mouse to the top-right corner of your screen, click the "Search" charm and enter "Sound" in the search box. Click "Sound" on the list of search results to open the Sound settings dialog. Select the "Recording" tab, click your microphone on the list of available recording devices and then speak into the microphone. If the grey bars next to the microphone on the Recording tab change green then the microphone is connected and passing an audio signal to your computer.
Troubleshooting a Microphone
If no signal is evident on the Recording tab, take a moment to troubleshoot the microphone. If it's a wireless mic, make sure its batteries are charged. If it's a wired mic, verify that it is connected securely to an audio-input port on your computer. When you've verified it's properly connected, make sure it's set as the default microphone for your computer. Return to the Recording tab in the Sound settings dialog, select the mic on the list of recording devices and click the "Set default" button. Click the "Properties" button to adjust the microphone volume and to verify that the Mute button is not engaged.