Why camera says one moment and does not seem to want to recognize computer
Most brands of cameras deliver a CD with the camera, containing software, needed to backup, transfer and work with the pictures you shot, to a computer.
Most of the time there is software is for both, Windows and MAC.
Before you connect the camera to any computer, you should install the software. The disk also has the drivers for the old operating systems.
If you lost the CD, or just don't know where it is right now, you can go to the site of your camera brand and try to download the software you need. For that look under support.
If your camera is old, and the brand does not exist anymore, try a freeware picture transfer / editing software pack. Like Gimp or Adobe Photoshop elements.
Just connecting a camera to a computer causes two things. The camera shuts down, and the computer won't recognise the camera. So nothing works.
If you can't get software form your brand, you always can install other generic software like Ulead, Pixir, BeFunkey, Gimp, Photoshop express. Or if that is not possible you could install an external memory card reader and download the pictures via de memory card reader.