My computer was working fine, but when I tried to write a message back to a friend on Facebook, every time I made a Key Stroke I would hear a clicking sound come from my computer and nothing would be typed on my computer.
This may happen if Filter Keys are on.
Open Control Panel > Ease of Access\Ease of Access Center > Make the keyboard easier to use
Here scroll down to “Turn on Filter Keys” option
De-select “Turn on Filter Keys”
Select the “Apply” button and “OK”