A less computer literate friend called me and asked if I can help restore his file. He regularly backed up his work file by dragging it into a USB stick, until

A less computer literate friend called me and asked if I can help restore his file. He regularly backed up his work file by dragging it into a USB stick, until one time he dragged the wrong way! He lost his recent work which was a big deal for him, as it was a whole chapter in a book he was writing that he believed turned out really well.. I suggested using Dropbox instead.