Hard drives can not be repaired. Well! OK! you can repair them but it would cost you an arm and a leg.
They are mechanical devices with moving parts. As with anything of that nature things can go wrong. They are run with electricity. This is the very reason you should back up anything you ever want to see again.
There are three technologies that are out there (at least available to the general public):
ATA (know a parallel ATA or just Parallel) These are the drives that have been around since PCs were invented. They did get faster and faster and smaller and lighter. Even the cost came way down.
Sata (Serial ATA or just Serial): These are a newer technology and even have a different cable that goes to the motherboard. A They are used quite a bit for Servers were more that one drive is used in what is known as an Array (R.A.I.D.). A I will not go into that at this time.
Solid State Drives: This is the latest and greatest technology. For now they are still expensive. They have no moving parts. They will last longer and are more reliable. They make no noise. You might call them a flash drive because that’s actually what they are based on. They also have less power consumption and run cooler. WARNING! If you do use one of these drives DO NOT Defrag it. It will shorten the life of the product.
If any one of these drive should happen to malfunction mechanically or electrically they must be replaced. A Virus can also destroy a drives ability to boot and/or store data. It can attack the boot sector so that the drive can not boot. There are places you can send these drives but it is very expensive. Even the evaluation can be hundreds of dollars.
