It sounds like your configuration settings have been changed.
The "click" on navigation is the sound associated with the Windows Explorer \ Complete Navigation Event, which you can check in Control Panel \ Sounds.
If there is a sound associated with it and it isn't playing, you have a problem (you can test in CP). If there is no associated sound, add one and see if it works.
The default sound level being low could be a configuration setting with your card, but I can't help as I've got a different card.
SD