How to recover data from damaged hard disk - Despite taking preventive measures or making backup copies, a hard drive fails and we can lose valuable information is within the possibilities of day to day given that the hard drive can suffer accidents, errors of various kinds, which has a certain useful life or something as basic as accidentally erasing a certain file .

When a hard drive is not recognized by our operating system, makes strange noises or directly seems " dead ", how to recover the information it contains, especially if it is personal and / or work and we do not have backup, is a must. Although depending on the type of error we will have to resort or not to a specialized company, there is software and some checks that can be very helpful to know the situation that we face and act accordingly to recover the information lost on a disk hard .

Types of hard drive failure: how to recognize them

Talking that a hard drive is broken can serve as an input to put us on alert but we must sharpen the diagnosis much more to know how we can act to try to recover the information. We say the information because the usual thing is that if a hard drive has been damaged, it is likely that we can recover the information but not continue using that unit safely.

Faced with a damaged hard drive, the first thing we need to know is if it is a physical or software failure. We will start by analyzing the physical part and for that, if it is an internal hard disk, the most convenient thing is to remove it from its usual place but keeping it connected , so that we can manipulate it comfortably. Do not forget to discharge static electricity before any operation with it.

"That the failure of the hard disk is physical / electronic or logical / software will determine that we can solve it ourselves and the amount of information that can be recovered"

Once the hard disk has been removed, we should check if the hard disk turns on or when it emits noises that we can not associate with the usual one when we have been working with it normally. If it does not make any noise when it is put into operation, and it does not appear that the discs rotate (in the case of mechanics), it must be ensured that there is no problem with the power supply . It is best to check that the cables are well connected and there is no damage to them. If in spite of everything it continues doing nothing, we can try to change the cables to discard that the fault is there.

Another simple and direct check to discard that the problem is to power the computer and not the hard drive is to connect it to another computer directly (if it works, the problem may be in the power supply of our equipment) or through an external casing .

In addition to the related to the feeding, between the electronic failures of a hard disk it is necessary to consider those related to the logical plate of the disc (PCB) or with the controller. A few years ago, looking for an exactly the same model and changing the PCB could be useful in very specific cases, but that task that seems simple input is almost impossible to do with current disks, which have some components such as the heads parameterized for that disk in concrete.

"The physical failures of hard drives usually require the intervention of specialized companies, with a high cost for the home user. In any case, the disc can no longer be used safely"

In these cases it is advisable to try to find solutions to PCB issues in technical services that have environment, tools and parts that could be used to recover the information that has been inaccessible on the hard disk.

If when connecting the hard disk it turns on but emits strange noises (the typical one is a repetitive clack-clack) it is necessary to begin to think that the problem is mechanical and due to errors of reading of the head by a displacement of the same one or that the plates They are damaged. Here a small stop: if you ever heard the "trick" of freezing the hard drive , unless your unit is very old and very low capacity, better not try. It will not work with the new materials of the dishes, which are no longer affected at that level by the heat, and there are more risks of losing the data completely than of solving the problem.

These head failures can be due to blows, continuous vibrations or degradation of the emulsion . In addition to the repetitive noise (can also start with noise and then turn off suddenly), the usual thing is that the unit is not recognized by the BIOS and usually fails to start the system.

"If we manage to make a hard drive with physical failure run for a while, all we have to do is clone it to try to recover the information in the copy and not the damaged disk"

In most cases of physical or electronic failures, it will require the intervention of a specialized company that will make changes or clean the head, transplant dishes, repair firmware modules ...

An important rule to comply with any failure of the hard drive is that, if we manage to recover it or that it works a sufficient time, the first thing must be to clone it to work on that copy and make sure we do not lose a base that is and that we could lose permanently acting directly on the damaged hard drive.

Repair a hard drive that fails or gives errors

When trying to recover information from a damaged hard disk , the best of situations is that the damage is not physical (or this has only caused bad sectors) but logical. The reasons can be numerous: a format not premeditated, corruption of files, deletion of certain documents or even a virus . In many of these cases, the user with the help of specific software can recover all or part of the information.

"If our disk has bad sectors we must act as soon as possible so that the information we can recover is as large as possible"

Starting from the situation in which the operating system starts but either a partition, external hard drive or even internal areas, are not accessible , there are different paths we can take to try to save the information .

If the error is due to bad sectors , which can be caused by degradation of the hard disk itself or by punctual spindle failures, the hard disk will be partially accessible and the action must be done immediately to prevent the problem from worsening. The usual thing is that we notice the symptoms by a sudden slowdown in the operation of the hard drive or even noise when it comes to accessing the area affected by these defective sectors.

Although all of the information can be recovered if the damage is not physical, even that of the defective sectors, there is no 100% guarantee that it will always occur as such.

The first thing to do if the operating system starts and we think there are errors in sectors, will be a hard disk diagnosis , which we can do with the function included in Windows to check for disk errors or free tools like CrystalDiskInfo , much more complete.

If we use the Windows tool from it, we can apply already solutions proposed by the same. Among them is CHKDSK, which allows us to perform a scanning and repair of the disk simply by commands. In terminal we write chkdsk x: / f substituting the letter x for the logical unit that we want to repair. We can also use the r command instead of f to detect bad sectors and retrieve the information.

"A hard disk with defective sectors, even repaired, is no longer reliable to store information that we do not want to lose"

If, with this action, the problem is not solved, we can resort to software specialized in repairing damaged sectors such as HDD Regenerator , which works in sectors with magnetization faults. Once the recovery process is finished, it is time to perform a cloning of the hard disk to start recovering the information of that unit.

If these methods do not work, you have to resort to more aggressive methods such as low-level formatting provided by tools such as HDD LLF or Lowvel . In these cases the information will no longer be recoverable but we can obtain a disk drive where, isolating the defective sectors in a partition, we can give it a non-essential use as it will be a matter of time before the disk can fail again.

How to recover deleted files

The simplest thing when working with a hard drive where we want to retrieve information is that we can use certain software to rescue images, data or documents that we have lost due to file corruption, formatting or file deletion by accident. The same applies to memory cards or USB disks in general.

"To recover a deleted file from a hard drive, the time it takes to delete it is the key to success in recovery. Try to save it when you can"

When a file is deleted from a hard disk, in reality what happens is that the operating system receives the information that the space that used to occupy an image or document is once again free to be used. Therefore the information is physically maintained and there is a good chance that we can retrieve it easily.

The most important thing when trying to recover deleted information from a hard drive is to do it as soon as possible , since both ourselves and the operating system itself could occupy that space with new information at any time and make it more complex and expensive to try to recover it. If the document to be recovered is of the utmost importance, it is best to disconnect the hard drive and use it as a slave in another computer to prevent the operating system from using it beyond what is necessary. And if we can, we must run the recovery software from a different unit than the one we are trying to analyze in search of the deleted file.

One of the simplest and most intuitive programs to recover deleted files is Recuva , Filerecovery or Pandora Recovery . In all of them a search of deleted files is carried out , of which we can know the state and if they are recoverable or not.

If we want to go further we can use TestDisk , which in addition to helping us recover files, can analyze drives, repair partitions, back up or work with boot errors from our PC. Another option is DDrescue .

If what we are looking for is something more specific for photos of memory cards, Undelete Plus can serve us perfectly.