Recovering data from an external hard disk drive is a very different process than doing so from an internal drive. External hard drive data recovery is basically just a process of undeleting files, since the drive doesn’t rely on an internally stored operating system for its own access. The one thing you do need when recovering data from an external drive is high data scanning speed, as these drives tend to be massive. The other issues you always have to watch out for with external drives is that if they have been reformatted or suffered physical damage, recovery of data can be extremely difficult and sometimes impossible.