How to transfer pictures from nikon d5000 to computer using USB?

My computer doesn't take memory cards and I can hook it up with USB and everything, but once I found something that transferred the pics but they were SUPER small and you couldnt even see them. Can someone help me out?

You should have had a disk that came with the camera, if not it should show up as a mass storage device under a drive number in my computer, or you could get a usb to sd card adapter