Never let your folks use your computer!
Dad needed my compure a week ago as a result of it a complete hard drive I use to stock some stuff of TV shows I loved, and even episodes has been erased.
I'm still busy trying to get everything back, and that all cause he mess up he formated the wrong drive, he wanted to format his USB stick, instead of that it was my disk which was super when I wanted to watch bones, (the last one of season 6 cause I love Booth's face at the end of the episode) but there was nothing there anymore.
So never let your folks with the computer alone when they don't know what they are doing.