Why Is It Not Possible To Easily Recover Data On A Hard Drive That Is Overwritten?

In some cases, you may be unable to find data on your hard drive and may be under the misconception that the data has been erased. You may think that your only solution now is to seek the help of a professional technician who can carry out some recovery of the data on your hard drive. However, you should know that the data is not actually missing and your computer is simply unable to locate the files you need. So, even if you take it to a professional, he will be unable to find the data because the information required to locate it, is missing.

In the case that the data you require has not been overwritten, it will be relatively easy for your technician to find this data. This is because all computer data is stored in the form of 1s and 0s on the computer’s hard drive using magnetic storage.

Hard drives use magnetism to store information

Car batteries and hard drives are similar in one main way- they both have magnetic poles. In hard drives, the magnetic poles are represented as 1 and 0 and all data is stored in a combination of these two digits. If the process of storage is to be explained in technical terms, it can be broken down into different parts. Firstly, the surface of the main HDD storage unit is ferromagnetic i.e. it attracts magnetic substances. Secondly, this surface’s main function is to divide all the binary codes i.e. combinations of 1 and 0 into magnetic regions representing either 1 or 0. Each of these regions is technically termed as a magnetic domain. According to the direction of the magnetism, data is split between these domains.

The two main ways of recording data are longitudinal recording and perpendicular recording. In longitudinal recording, data was stored depending on whether the magnetism was right or left. In perpendicular recording as the name suggests, the data is stored vertically and perpendicularly. The evolution of data recording from longitudinal to perpendicular has happened after 2005.

What happens when data is overwritten?

When you attempt to over write data, your computer indicates that the space occupied by the old data is actually vacant. It does not make new space for the more recent data. Therefore, when data is overwritten, the old data is replaced with new data by your computer or laptop’s operating system. This basically means that the old data has been deleted and no longer exists. Therefore, no recovery tool or professional technician can recover data that has been over written- because it cannot be found on the drive after it has been deleted!

Additionally, when data is overwritten, the magnetic domains get re-magnetise to form a new combination of the binary code. It is extremely hard to recover data once this process is complete.

Laptop data recovery is a long shot and practically impossibly after data is overwritten

The only way to recover your data after it has been overwritten, and even this is a very slim chance- is by using a magnetic force microscope. What this device essentially does is re-magnetizes the two magnetic domains to try to revert it back to its previous state. Take care to ensure that your new data is not lost in the process of trying to find your old data!

Related posts

Leave a Comment