My Book Essential cant transfer files

HI guys i am new here, I have a 1tb my book essential that I have been using with my Bell satellite tv to record tv shows. Mostly cartoons for my grandson I tried today to hook it up to my computer so I could transfer some of the shows to a usb for him to watch on a leap pad. But my hard drive doesn’t show up under my computer, but does show up as a usb media in my task bar, but when I click on it it does nothing. I don’t want to format it as I will loose all the cartoons is there something I am missing. PS this is the first time I have tried it on my desk top Thanks for your help

No Ideas guys