It's not advisable to transfer all files from a DVD to an external hard drive directly by a simple copy & paste, since virtually all commercial DVDs are copy-protected to prevent illegal distribution. The correct way is to use the right DVD copy software to remove DVD copy protection and get complete digital copies of a DVD first, and then transfer them to your external hard drive. WonderFox DVD Ripper Pro is a recommended good assistant that can not only convert DVDs to MP4 and 500+ optimized formats and devices, but also create ISO images or Video_TS folders from DVDs for 1:1 intact backup. Download the program and jump in how to put DVDs on external hard drive in the next part.