A clicking hard drive or storage device typically indicates a mechanical problem with the drive in question.  Sometimes it can also be due to file corruption on the surface of the heads, which results in a clicking noise when the actuator arms are seeking over the media.  The arms will repeatedly not be able to read a certain area, and thus will sometimes start clicking back and forth.  The noise can also result from physical damage to the arms which is causing them to malfunction within the drive.

It is extremely important to turn off your drive and leave it off as soon as a noise like this is discovered eminating from a hard drive.  Running the drive any longer than necessary can result in permanent physical damage to the drive.  Often times the actuator arms will click back and forth rapidly and can lead to severe, permanent damage to the media.  These cases require the expertise of a data recovery company that can fix severe mechanical or electrical problems beyond the scope of a simple logical disk recovery.

InterData will evaluate your case absolutely free, and provide a comprehensive quote.