I wonder what is happening as well?? Did you try unplugging all connections and restarting your PC. Then reconnecting? Then if that doesn't work...try unplugging, turning off PC, reconnecting, and turning your PC on again with everything all hooked up.
Side note...if you go to unplug your external hard drive please make sure you don't simply unplug it. You should see an icon on the bottom right corner of your screen that when right clicked will give you options to unplug your drive.