The only way to ensure that your data is completely safe is to have a decent data recovery strategy, with an up-to-date backup of all your files, and an external hard drive is a cheap solution. There are, however, pros and cons to using an external hard drive to backup your data.

Creating a backup of your files is simple – just connect your external hard drive to the computer via the USB port, and drag and drop the files and/or folders into it. Alternatively, you can use a backup software utility to guide you through the process. Once the transfer is complete, unplug the drive – this is especially important as viruses and malware won’t be able to touch it – and store it in a safe location. In the event of you needing data recovery, all you need to do is restore the files on the drive. 

There is a massive difference between backup and simply utilising an external hard drive as extra disk space. With storage, you can modify and access the data regularly. Additionally, as mentioned above, with drives constantly connected, your data is at risk from malware. If your machine is infected, it's likely this will spread to include any external devices connected, meaning the only chance of getting your data back is professional data recovery. Backups, on the other hand, are often kept in a read-only state, meaning they can’t be modified. The purpose of a backup is to provide you with a copy of your files - a complete data recovery solution - so that in the event of a total system failure, you will always have a copy of your data to restore.

With external hard drives, you can backup your entire system for an extremely low cost – you can buy 1TB external drives for as low as £50. This will typically be enough for the average user to store thousands of documents, photos and videos. That said, though, they aren’t perfect. External hard disk drives, like all drives with moving parts, will eventually fail. While you can employ the same data recovery techniques with external hard disk drives as you can with regular ones, it's something you want to avoid. Your external hard drive will have what’s known as a Mean Time Before Failure (MTBF), which is typically around 3 years. But, this is the average lifespan assuming the drive is kept in the optimum conditions and not damaged in any way, like being dropped or submerged in water. Some non-hardware issues, like an accidentally deleted partition or bad sectors, may be fixable using free file recovery software