ok, this is because you need in camera software to open the file.
When you plug in the camera (assuming your running on any windows version)
open up your MY COMPUTER, and find out which drive your camera is plugged into,
maybe H or G or something, or maybe a picture of a camera, well, once you figure it out,
open it, and you should find some folders your pics are stored in, just click and drag your pics (or the entire folder) out of there and to your desktop or your my documents or wherever.
If this sounds to complicated, when you plug in your camera, don't use the camera's software, a menu should pop up asking what to do, you can click "Open and Explore Files" or something, it will have a folder icon, and you can do what I said above from there,
OR,
From the menu that should pop up asking what to do, click "Transfer photos using windows scanner and camera program" or something like that.
You can also find that program in START > programs > accessories > Scanner and camera wizard.
Hope that helps.