SD card wont import media videos. How to fix this?

I just got a JVC Everio camcorder and now im trying to upload my footage. Whenever I plug it in to my computer with the USB or card reader, I get the message "No new pictures or videos were found" I dont have a extra computer to use. How do I fix this? I already tried restarting my computer and that didnt work. This is really frustrating. Id really appreciate some help