There is this "BOT" that invades machines to click links to rack up 'points' or money.
I'd scan the machine with EWIDO and HOUSECALL. Also read http://windows.about.com/od/tipsarchive/l/bltip567.htm
Hopefully you find your machine free from pests.
clicking noises all the time even when im not near the computer like the clicking noises when u view webpages