Many of us believe that in order to permanently remove data from a device, we merely need to click ‘delete’ then empty our recycle bin. Whilst this certainly frees up storage space and makes it appear as though the relevant data no longer exists, this is simply not the case.

When you complete the actions outlined above, you inform your machine that you no longer require access to the relevant data. The machine therefore marks the space that contains this data as writeable. In other words, it does not delete it, but merely earmarks it as data that can be overwritten with new data should it be necessary. So, if you take no further steps, then the data in question will remain on the drive until it is overwritten. If you’re using a Windows operating system then this data could be overwritten at any time as this system will indiscriminately write files to any viable location (unless you are using an SSD and have the correct drivers installed). Other operating systems such as OSX and Linux will automatically save new data to sections of the drive that have not held data previously.

If you therefore accidentally delete a file and want to recover it, then you should do it as soon as possible, but speed is even more of the essence if you’re using a Windows system with a HDD as the data could be permanently overwritten at any time whereas – provided the device’s drive still has a reasonable amount of free space that has not previously held data – you have a little more time with other operating systems.

Should you be deleting data because you intend to sell the device that contains the drive or simply do not want anyone to access the data in question, you’re going to need to ensure that it is the data itself, and not just the links to the files, that have been deleted. If you’re using an OSX operating system then you can do this by placing the relevant files in your recycle bin and then clicking on the ‘Secure Empty Trash’ option that can be located by activating the Finder Menu. If you’re using a Windows operating system, then you’ll need to do one of the following:

Download Some Software

A number of free programmes that will permanently delete sensitive data are available online. Simply search for ‘Secure File Delete for Windows’ and, one you’ve found some software that’ll do the job, download it and follow the instructions. You will need to remain vigilant and make sure that you have anti-virus software running to avoid downloading malware and other harmful programmes.

Save New Files

If you have the patience, then you can simply save a large file to your drive and then continuously copy this until it fills your drive as this will result in the sensitive data that was stored on the drive previously being overwritten. Just make sure that the file you continuously copy contains non-sensitive data only.

Destroy the Drive

It may seem extreme, but it you want the peace of mind that comes from knowing that there is absolutely no way that anyone will be able to access your data, then you’re going to need to destroy the drive. There are numerous (fun) ways of doing this from burning it to smashing it with a hammer. Check out Google and get creative.