Have you ever looked for a document on your hard disk which you had just been editing - and now it's gone? For some unknown reason, the file had simply vanished. Ideally, backing up your most important files helps you out even BEFORE you actually lose any data. How this works, the tools you need and the methods you can use to give your data effective, long-term protection is covered in our article on backups.

After experiencing such an incident, you know that data stored on the hard disk will not always be safe and accessible for ever. Accordingly, the best approach is to save your files regularly and back them up to an external medium. The ways in which this can be done - which range from a variety of storage methods to the use of professional backup software - will be covered at the end. Our video covers the most important details:

From short circuits to software errors, there are many hazards to which your data is exposed. One of the commonest of these, and a regular risk for data loss, is failing to perform a full computer shutdown. In the case of a power outage or someone simply switching the computer off in a fit of impatience, disk write processes cannot be completed and data is lost rather than saved.

Computer malware such as viruses and worms or hacker attacks also frequently lead to situations where data is damaged or (in the case of ransomware) is encrypted and rendered inaccessible. While users can reduce the risk of threats like these affecting their own devices, any computer system can in principle become infected at any time.

In addition, data files are often overwritten by mistake. This can happen if you use an existing text file as a template for a new document, for example: you merely need to edit the document and then forget to save it with a new name. Buggy programs can also overwrite data that you actually wanted to keep.

Perhaps one of the commonest causes of data loss is simply deleting the files yourself by mistake. Most popular operating systems offer some sort of recycle bin to let you undo this action. Files that are deleted are sent to the bin to start with and can be restored from there at any time. When you empty the recycle bin, however, any files in the bin are typically erased permanently. This also happens if you have set up the recycle bin to erase data automatically on a regular basis.