Hi Keith,
You should only connect the USB cable after the software installation has finished to complete the process. If you have 64 bit version of Windows you will also require to download and install the 64bit drivers before connecting the cable. Uninstall the previous version(s) before installing the new one but remember first of all to save your mylog, photos, logos, silhouettes etc collections which you may have been building up over the course of time and replace the ones from the new installation with them.
Also remember to install to C:\Airnav and not to a program files location.
Alan