Second Monitor "No SIgnal"

I am just setting up a plugable docking station. I am using WIndows 7. Everything works fine (keyborard, mouse, printer, scanner etc) except the monitor. I am connected through the DVI. The monitor shows “No Signal”. I seem to be able to see a second monitor in control panel. Unfortunately, everytime I plug in the second monitor, my laptop screen zooms into a small part of the desktop and I have no control. Any suggestions?