Nikon Camera Control Pro 2 not seeing D5100
Have you read the instruction book that came with your camera about teathering? You may have to change a setting in your menu.
I had Issues with other brands of software and my D200. I ended up settling on Nkremote. It sync's every time and from the small handful I tested, it is the fastest at showing images on screen. Do you have lightroom? LR4 can do teather..