A PC hard drive is probably one of the most important parts of a computer. Basically, it is responsible for the physical storage of information which it does by way of magnetic disks. Here are 3 ways hard drives fail:
1) Normal wear and tear are possible due to the moving parts needed to retrieve the data on the hard drive. Data is constantly being transferred to and from locations so eventually, disk parts are bound to die.
2) Power surges among other electrical related issues can cause a hard drive to fail.
3) Logical disk errors such as software corruption, unexpected OS failures or computer viruses. This could also include the accidental formatting of a drive or deleting files without a current backup.
Usually, physical drive errors can not be fixed at home and will probably require a disk recovery utility from some well known company that specializes in data recovery. Hard drive recovery is possible because the data continues to exist on the hard disk even after it is deleted. Unless data is overwritten in the same sector, the data will continue to exist even if the operating system does not show it.
As for logical drive errors, data can be copied to an external disk, then the affected drive can be reformatted with the original OS. Data can then be restored to the original settings. I accomplish this task at least one a week at my current job.
Data recovery companies are generally used by businesses that can afford them as the price could cost thousands of dollars. Most of the programs they use can be installed easily and can be scheduled for self-maintenance such as taking a periodic backup of important files.
Backup your important files today! Your hard drive could fail at anytime.