How to fix and install the built in microphone of Acer Laptop

i accidentally deleted my microphone in the sound devices. how do i install my built in microphone its not working now.

1. Right click the sound icon in the lower right of the screen, near the clock and select 'open volume control'. Next click 'options' and select 'properties'. Click 'recording' and make sure that 'mic' is checked. Make sur ethat it is not muted either.