How To Completely Wipe Data From Your PC

 

How To Completely Wipe Data From Your PC

There has been a lot of talk about the right to be forgotten on the Internet , but what about the right to Data Wipe from our own devices . Fortunately, there is no legislation on that, but there is a lot of ignorance that can lead us to involuntarily share data with strangers when we get rid of our PC, either because we sell it or give it away, and even when we take it with total confidence to a service repair thinking that we have previously deleted all the sensitive data that we had on it.

The data handled by a computer can basically be stored in RAM memory or on the hard disk. In the case of RAM, there is no problem, because it is volatile memory that when you turn off the computer and there is no electrical current, it loses the information it had stored. This is generally true, although there are techniques that allow you to retrieve certain information from RAM by keeping the temperature at -15ºC or even a little less. But they are very specialized techniques and in general we should not worry too much, for now.

On the other hand, the information that is stored on the computer's hard drive is persistent information that is stored so that it remains, until it is decided to delete it and then we lose it forever ... or not.

Disc types

We can find two types of hard drives in our computers, the traditional ones ( Hard Disk Drive - HDD) and the more modern solid state drives ( Solid State Drive - SDD). The reason why we differentiate between the two in this article is motivated by their different behavior that conditions the secure deletion of the data they contain.

Hard disk (HDD)

When we delete files by sending them to the recycle bin and we confidently go to “Empty Trash " to be sure that what we have deleted cannot be recovered, we are still far from truly deleting the information . The only thing that has happened with this operation is that the data, that is, the bits that make up the file that we have eliminated are no longer localizable. 

But the data is still there, it has not disappeared. It's kind of like that famous scene from Fargo, when you stop your car on the road with a completely snowy gutter and a guy buries a briefcase of money under the snow. As soon as he is finished, he leaves a mark in the place where he has buried it to be able to recover it later. Imagine that that sign disappears because someone or just the snow makes it no longer visible. One could stop at the gutter, look from side to side and have the impression that there is nothing there. But in reality the briefcase is buried just like your data. And all you need is special software that is capable of recognizing certain patterns in the arrangement of the bits. So that it finds the headers of the deleted file and the rest is sewing and singing. In short, deleting a file and emptying the trash or even doing a logical formatting of the disk does not ensure that your data disappears; it is only hidden at that moment. 

Solid State Disk (SSD)

Solid state drives have a different behavior and when files are deleted, if your operating system is Windows 7 or higher, Mac OS X 10.6.8 or higher, or a Linux distribution with the kernel version equal to or higher than 2.6. 28, the system itself implements a special function (TRIM) that overwrites the bits of the file with zeros immediately after deleting it, thus preventing the recovery of this data.

Safe Data Wiping

If you need to be sure that your data wiping has been done from the hard drive, my suggestion is to use one of the following tools depending on what you want to achieve.

If your goal is simply to make sure that some files you have deleted have actually been deleted, then your application is Bleach bit. Not only does it overwrite the free space on the hard drive to prevent deleted files from being recovered, but it also helps you free up disk space by emptying temporary directories, browser history, cookies, logs, etc. And there is a version for Linux and Windows. It is an open source development and its license is GNU General Public License.

If instead we are talking about getting rid of your PC and you need the entire hard drive to be safely do Data Wiping, then my recommendation is without a doubt Darik’s Boot and Nuke. 

It is an image (ISO file) that you can burn to a CD / DVD (here are instructions on how to do it, for example, in Windows 7) to boot the computer from the CD / DVD and follow the steps indicated to proceed to the complete hard drive wiping safely.