Hello, I’m Nathan, and I’ll be assisting you today. My livelihood depends on your positive feedback, so your satisfaction is my highest priority.
Sorry to hear you’re having trouble.
Most computers do not have a built in card reader, this is normal.
Try connecting the usb, turn the camera on, but set it to the PLAYBACK mode (the same you'd use to look at pictures on the cameras own screen).
If that doesn't work, then the issue is coming down to your newer computers not having appropriate drivers for the old camera.
You can get around that by buying a simple external card reader to connect to the computers instead: http://amzn.to/1VcFI3p