When the hard drive is not physically damaged it is called a logical failure. In a logical failure, the parts of the drive are undamaged, and the computer cannot read the drive. Failure is caused by either corruption of file system or an accidental formatting. When the drive is overwritten all your data is lost.
You will know your drive has a mechanical failure when it makes a clicking sound. It is wise to dislodge it, as using a damaged drive may lead to total failure. It is good to call the experts and have the data moved to a new drive. If you are able to hook up the drive to another PC, you can move the data yourself. In case of a virus corruption, or a bad sector you can run diagnostic software to check and fix the problem.
Hard drive failure data recovery experts can charge from $500 to $2500, to recover data lost due to a logical or mechanical failure. If the problem is only logical you can attempt to recover it your self. For mechanical failures call the experts.
Many online diagnosis software for both Windows and Mac computers are downloadable, and easy to use. You can find where the problem is, and how much data is recoverable. Prosoft’s Data Rescue PC, Ontrack EasyRecovery DataRecovery and RecoverMyFiles are all priced low. The data recovery process can be slow depending on the amount and type of data you have. You will also not get the files back in the same way as you organized them. The software will just dump these from one drive to another, and you will have to sort files and organize the folders again. File names will also be changed, so you will have to rename the files.
External hard drive data recovery is similar. These External USB and Firewire disks are more prone to failures because of their casing. There is no adequate ventilation, so the unit heats up and the disk crashes. The disks are also more prone to accidents. They get dropped and knocked over easily.
When the external drive has been dropped, it makes a ticking noise at start up. This signifies damage caused to the read and writer heads or the motor. In some cases, both can be damaged. Recovery of data at this stage is possible, if you stop using it. When knocked over, it makes a buzzing sound because of a seized spindle. Recovering data is always possible from such a drive. When the drive overheats, it will conk off and the system will not be able to read it, even if it does, it will be very slow to operate. Use a diagnostic tool to search your data and recover it. Data recovery is easy in case of overheating as compared to loss caused by physical damage.
Hard disks are very cheap these days and it is a good idea to get a back up drive, so you do not face the same problem again. Maintaining your PC health will ensure it does not catch a virus and build a bad sector. Always buy a new hard drive for your computer.
All in all, hard drive failures are either logical or mechanical. You can attempt to recover data in a logical failure, while for mechanical failures calling an expert is a good option. External hard drive data recovery is similar. It is wise to have a back up program for easy recovery of data.