Downloading pictures from Nikon L16

I've been helping my mother with her new Nikon Coolpix L16 and downloading pictures to her computer. I followed the instructions for the software that came with the camera and installed in on her computer. When I connect the camera to her computer, the camera never pops up on the screen. When I connect it to my computer, an icon pops up almost immediately labeled as an L16 (even though I have not installed the software on my computer.) What could the problem be on my mother's computer? We both run Windows XP.