After suffering with PC problems I decided to buy an imac from Apple. I loaded Windows 7 on it and then connected my 3d radar bax to it and downloaded the installation. After communicating by e mail with Airnav because I could not log on, I was given a username and password to get on. But the system still does not work. That's all I can see on the screen is the large Google Earth and nothing else. Does anyone have any ideas of what I might be doing wrong? the system worked fine on the PC