Unfortunately, this is The Click of Death. The short explanation is that your drive has experienced an unrecoverable failure. So, you're going to need a replacement drive. In some cases, it's possible to recover data from the old drive by freezing it and then doing a data transfer, but you need some preparation for this. First of all you need a working computer and a drive with sufficient capacity for the transfer, and it has to available for immediate use after you pull the drive out of the freezer. Of course, if you practice good backup procedures, you can skip the whole freezing thing. But, just in case, here's how it works. Pop the old drive into a Ziploc bag, place in the freezer for several hours, then immediately connect to the computer you want to use for the transfer, and copy your data. You'll find some who say this doesn't work with The Click of Death, but sometimes it does . Normally, this is a one shot attempt. So, restoring a backup to the new drive is certainly the best approach, but if you need the data of the dead drive and don't have it backed up, you really have nothing to lose.