Deleted movie files by mistake from my external hard drive, how do I recover them?
You should be able to do this with PhotoRec, arguably the best file recovery software out there. You can download it here: http://www.cgsecurity.org/wiki/PhotoRec
You can also check out our article all about it here: //www.makeuseof.com/tag/recover-accidentally-deleted-files-from-any-os-with-photorec-windows-mac-linux/
Failing that, there's always the bigger brother, TestDisk (though PhotoRec handles video files fine, so I don't think you'll need this): http://www.cgsecurity.org/wiki/TestDisk
You can use the following methods mentioned in the below articles to recover your file -
Recover Deleted Files from Flash Drive/External Hard Drive/Recycle Bin [using EaseUS undelete]
How to Get Deleted Files Back from USB or Hard Drive [using Recuva]
Install Recuva from http://www.piriform.com/recuva . Connect your external hard drive.
Method of recovering is explained here : http://www.piriform.com/docs/recuva
I'd like to note that it is best to recover data and files from the deleted location (external drive) to another physical media (your internal hard drive, flash drive, SD card, another external drive, etc.). This is because you do not want any data written onto the drive with the deleted file or else the file may become overwritten, thus becoming lost or damaged.
If you haven't saved other data on your external drive since the deletion, your chances of recovering the files are high.