Digital camera-to-computer USB connection

Although I've tried installing a new battery into my camera, used 3 different USB cables, and tried on two different computers, I cannot get my camera recognized; therefore, I cannot download the photos stored in it. Please - can you help?

The camera is a Minolta Maxxum D; the computer is a Dell Inspiron laptop running XP. I've downloaded literally dozens of photos to this computer from this camera; suddenly, it doesn't work.

Thank you very much for any help; there are no camera shops around here.

Sharon