You must open your computer case,take the hard disk drive out and on the paper stick which is attached to the hard disk drive it will be written what model it is,what year it is made in,size of the hard disk drive and so on blablabla.
Also do what johnb35 told you.Copy ALL your important data from that hard disk drive NOW otherwise it will be too late later trust me!
By the way if the hard disk drive stops working completely once you try to backup your files,in that case try putting that hard disk drive in a VERY cold place such as a fridge or even freezer for AT LEAST 2 hours.After 2 hours,take the hard disk drive out fast and immediately put it in your computer and plug the wires as fast as you can then turn on the computer and if the hard disk drive is now working,in that case do NOT do ANYTHING!Just try to backup ALL your important data IMMEDIATELY!
If the hard disk drive is still not working,then your only chance is to open the hard disk drive and replace the heads that are reading the data from the platterns.
NOTE 1: The heads must be taken from the EXACT hard disk drive model that is in your computer!
NOTE 2: Do NOT open the hard disk drive outside of the CLEAN room!
NOTE 3: Be sure to wear clean glaves and do NOT touch the platterns at all!
NOTE 4: Be sure while pulling out the magnet because if you do it wrong,you can really damage the hard disk drive mechanical parts and in that case you are totally screwed!
I bet that he is using the Western digital or Toshiba hard disk drive because this clicking (dying

) sound is very often with them.But hey who knows...maybe it's not.
Thank God I stopped buying Western digital and Toshiba hard disk drives long time ago.

Each one I had died within 2 months lol.
Maybe I would continue buying cheap WD drives if I have my own clean room because in that case I would at least be able to repair them myself for free lol,but since I do not have the clean room,I would rather buy Seagate drives then pay 1000 dollars to a service that would do the same thing I would do in the clean room lol.
Damn too bad I don't have one xD !
From now on I am saving money for a clean room xD ! It's time to raise dead HDDs from the death! =D
And in the dawn they will raise!...DAWN OF THE DEAD!
Oh btw that movie was some scary sh!!it =D