No one wants to lose their data and that is why backing up your data is essential. What goes along with backups? Testing the restore process.
Sometimes programs malfunction and give a successful backup notification, even if the backup process didn’t work, or if it missed files. Some backup programs allow you to choose what files to backup; what happens if a setting accidentally gets changed so there are no selected files? This is why you should test the restore process ahead of time.
Most backup programs create their own file that can only be read by the backup program. You can try installing your backup program on another computer, plugging in your external device (the one which contains your backups), and running through the restore process. If all of your files restore to how they were on your computer, then your backup program is doing its job and working as expected. But let’s say you perform the test restore, only to find out your backup program wasn’t even working. Doing this ahead of time means you will be able to correct the errors and actually get your data backed up.
Testing the restore process also gives you a little more experience in learning how the program works. This way, when it comes time to rely on the backup program, you will already know how to do the restore without any added frustration created by rushing to get your data back.