I don't know what desktop you are using (Mate?.. Cinnamon?) But I am running Mint 17 Mate. What you should need to do is go to Menu > Control Center > Preferred Applications. Once there you should go to the Multimedia tab and set what you want to be the default for videos. Hopefully that works for you!
P.S. I LOVE your signature turtlebay! Very good choice!
Dell Dimension E310 desktop, 2.80 GHz, 2 GB DDR2, 500 GB HDD - Linux Mint 17.2 (Mate 32bit)
Acer Aspire One KAV60 netbook, 2 GB DDR2, 120 GB HDD - Ubuntu MATE 15.04 (32bit)