Here's an interesting data recovery case I recently looked at.
2TB External Seagate Drive
1. Took hardrive out of desktop this morning and put it in my bag to use with my laptop later, I believe this may be when files were initially corrupted.
2. Tried to save a text file, on my laptop, on the external drive, and it gave error "The file is corrupted or unreadable"
3. Made copies of open text files in text editor and saved them. At this point I only suspected that my folder of text files was corrupted.
4. Came home and reconnected external hard-drive to desktop, tried to fix this issue, started following this guide: https://www.easeus.com/resource/file-or-directory-is-corrupted-and-unreadable.html
5. After navigating to the drive in command line I executed the command 'chkdsk /f f':
6. I think (not exactly sure on this step) I responded to a command that asked for a 'y/n' response with 'y'. I think it was asking for the drive to be unmounted? I don't really remember the details other than that I responded to a 'y/n' command.
7. Looked at the drive and saw that many files and folders were missing, not just the folder with text files. All of my folders in 'Skewl Documents', as well as many movies and a lot of music.
8. Started looking into fixing this issue with this guide: http://www.minitool.com/data-recovery/recover-data-after-chkdsk.html but decided against it, after remembering that I didn't have any drives bigger than 2TB to backup the corrupted drive to
9. Copied over the copies of text documents I made to desktop
10. Manually disconnected the drive as it refused to eject (although it always did this). My flatmate had told me it was better to eject it sooner rather than later as temporary files writing over the drive could overwrite some of my lost data.
11. After looking online I realise that my lost files may have been moved by the 'chkdsk' command into a hidden folder, with just the file endings being unrecognisable and they may be easily recoverable, but at this point I don't want to risk plugging it back in.