If your computer doesn't detect your microphone at all, the problem is usually physical or driver-related. For USB mics: unplug, wait 5 seconds, plug into a different USB port (avoid hubs), and check if the device appears in your OS sound settings. On Windows, open Device Manager > Audio inputs and outputs and look for your mic — if it has a yellow warning icon, right-click and update the driver. For Bluetooth headsets, forget the device and pair again. For built-in laptop mics, restart the computer first. On Mac, try resetting the audio subsystem: open Terminal and run "sudo killall coreaudiod" then check System Settings > Sound > Input. If the mic works on another computer but not yours, try installing the manufacturer's driver from their website instead of relying on generic OS drivers.