Western Digital drives.
If you hear that clicking noise when the drive's flat data cable is disconnected from the drive and the drive is ONLY connected to its power cable, then I'm afraid your drive is unable to put itself "online" and is completely inaccessible from the outside world.
This "power cable only" test is what the Western Digital Technical Support people had us perform in order to diagnose a dead drive ... and it's conclusive. If, however, this clicking happens later on, after the drive is up and running and you're only trying to read a particular file -- then the great majority of your data probably is recoverable.
Western Digital's is Data Lifeguard Tools http://support.wdc.com/download/index.asp#dlgtools
They also have a diagnostic program you can run from their site that will check the drive and tell you if it's ok or not. Your drive may still be under warranty and they will replace it as well.
If it's not a WD drive, let us know....I have links to other mfr sites that have similar tools available.
I am using a Dell Deminsion 8100-Pentium 4--60GB Ultra ATA Hard Drive. Recently the hard drive is clicking loudly, occassionly, first 1X-then 2-3X, while the drive is clicking the OS freezes up, nothing works, then after a 'whizz noise' it continues back to working. I've used every system check, scan-disk, defrag, and the only info it shows in "Complete-defrag" that there 'may' be physical damage to my hard-drive. But then it may work for days and the error will not show up, then the next time I turn it on, there it is again. I took the front case off to be sure it is the hard drive 'clicking', it is for sure. Should I go ahead and replace the hard-drive or wait for it to shut-down completely, second, I have an external 120 gig hard drive-how can I do a complete Drive C backup to this external drive for the install of the new hard drive?