How do you install a TWAIN driver? My Polaroid Izone 550 usually downloads pictures easily..?

But i have been having to turn my pc off & on alot lately, and now when i plug the camera into the base, it says i can't retreive pictures because there is no TWAIN driver. What in the world IS that, and how do i install it? I tried the add hardware & device manager with no avail.. somebody, please help me!