Who has not suffered a digital accident in which you have lost valuable files from your computer? From deleting files by mistake or mistaking the unit for formatting, to having the bad luck that a fault occurs in the software or in the operating system … there are many causes that can leave us without our most valuable files.
Faced with this situation, many people resort to “home” remedies and try to recover lost data by themselves, through the use of some kind of data recovery software that scans the disk drive in search of lost or deleted files.
Depending on the extent of the damage to the internal logical structure of the unit, these types of programs can be more or less effective. Sometimes, thanks to them it is possible to locate and extract from the disk some of the lost files.
But beware! Sometimes the greatest risk can be the user himself if he does not operate in the right way.
Why is it possible to recover a deleted file?
To understand it in a basic way, let’s think that the file is physically recorded on a magnetic plate of the hard disk, in a specific position. The hard drive data recovery has an index that indicates the position of each file.
When a file is deleted, only its index reference is deleted. Actually, the “deleted” file is still there. However, now its position appears as an available space to record other files.
Be careful when choosing the destination of the recovered data
When the user tries to recover the data by software, it may happen that he does not have at that moment another separate disk unit. And you may decide to save the recovered data in another folder within the same unit affected by the problem.
The user asks: “If there is enough free space, why not save them in another folder of the same unit?”. The answer that a professional would give to this question is that “it is a very bad idea”.
Why is it a bad idea? When the files have been deleted (either intentionally, by mistake, or by a software failure), the position they occupy in the disk drive is considered by the operating system as free and usable space.
Therefore, when creating a “new” folder, we can not know if that folder is in a “new” space (that has not been previously occupied) or it is a reused space. If it is a reused space, it may happen that the bits of information that make up our precious lost files are quietly found in it.
Files recovered but … corrupt?
When launching the recovery software, it will order the operating system to write data to the disk, and the system will begin to reuse or overwrite the area where our deleted or lost files were located.
This process can cause our files to be partially or completely overwritten, thus being useless even if we recover them (see infographic below).
In other words: while we are recovering some files, we are destroying others. The result of this is a data recovery in which there will be a few files recovered correctly, and a large majority of corrupt files that are not opened or displayed correctly, having already been irretrievably destroyed.
In conclusion, if you ever choose to recover the files yourself, always save the recovered files to another physical disk drive than the one affected by the problem. This will avoid the overwriting of the data and its irremediable loss. However, if you want to get better results and not take any risk, put your disk in the hands of data recovery professionals. At Ondata, you can request diagnosis and budget for data recovery without commitment.