http://www.techradar.com/news/software/applications/best-free-data-recovery-tools-1321723

File recovery can be an expensive business, which is why it's no substitute for backing up your key documents, photos and other data on a regular basis. But that's of little comfort to anyone – even those with good backup regimens – who suddenly find themselves confronted by the stomach-churning feeling of data loss.

Whether it's a virus infection, a hardware failure, or just human error, it's all too easy to lose vital files. As soon as you've become aware of data loss, it's critical you stop using the drive affected immediately. Whether the drive itself is failing or you've simply deleted a file accidentally, this is the golden moment when you may be able to get your data back before it's gone for good.