Don't forget too that ANY USB device is a drive in the MY COMPUTER section. This means opening the drive thru my computer SHOULD show the DEVICE. If it doesn't show it there, your driver is not installed right - that is if you CAN see and ACCESS the VIDEO and IMAGE FILES.
I like managing and viewing files through MY COMPUTER and see which drive it is. If you see no video or images, but you can see into every folder of the cameras storage, then there are no files there. Sounds like it may be ALL INTERNAL MEMORY? As Kathy mentioned a card or disk or tape, digital is such a unique media.
DOES the content play on the camera ok?? If its any of the above devices, except internal memory which has to get plucked from the camera.
I HAD THE OPOSITE PROBLEM: when my wife and I got married, it was sort of an elope getaway thing to our favorite city, Madison, Wisc. My camera was a pocket 110 but took great photos, it wasn't a cheap camera. Unknown to me, the mechanism which cause the lens to popout when the flash is raised malfuctions, and NOT ONE SINGLE PHOTO out of 5 rolls came out - not one of my marriage under the state cappitol, read to us by the highest ranking judge in the state - wild city of College Kids, makes us feel young :)
Married was and is fine, but NO MEMORIES to look at. It was then I bought my first digital 1998 a Sony Mavica (images on floppy disks) and things got better from there. I'll never even guess if a image came out good, why look at it when you can take 5 others to be sure - tons of freakin room on a digital memory chip/
Good luck, let us know. Wish I could tell you more, likely you knew that alread, but some people don't.