Recuva
Recuva is a free file recovery software that can recover pictures, music, documents, videos, emails or any other file type you’ve lost. It can recover from any rewritable media you have: memory cards, external hard drives, USB sticks and more! Recuva is one of the best free data recovery software tools available. It's very easy to use, but has many optional advanced features as well. It can recover files from hard drives, external drives (USB drives, etc.), BD/DVD/CD discs, and memory cards. This program can even undelete files from your iPod!