|If this is for a keyboard for a desktop computer, or for an external keyboard connected to a laptop or netbook computer, if the clicking sound is being generated by the keyboard itself even when the computer is NOT running, the only thing you can do is to use a different keyboard that doesn't make that sound as loud. |
If the sound is being generated by software via the speakers on or connected to the computer, you need to figure out which software is responsible for the clicking sound and disable that feature in it's settings.
E.g. the software for an external keyboard that you installed yourself, or that was automatically installed by Windows when the external keyboard was plugged in, or that was already installed in the original brand name system software installation, in which case the settings for it are probably in Control Panel - (Classic view) - Keyboard
It's also possible for a laptop or netbook computer that there may be a key combo that toggles the clicking sound off / on - see the User's or Owner's manual for your model .