Hi Birdie
Screen Shots will be AirNav RadarBox folder. If you've got Vista or Windows 7 and you've followed the installation advice on the forum it should be easy to find. I suspect, though, that you've installed using the default installation setting, and the folder is in the Virtual Store.
You may need to explore that - in the Users folder - to find the Screen Shots folder.
It may help to do another Screen Shot, and when RadarBox asks, tell it to open the picture. If you then use "Save As", your viewing program should show you the path to the folder that the picture is in.
Hope that helps
Rod