I experienced similar problems with Windows 8, eventually realising the problem revolved about my laptop not recognising the radarbox.
If my memory serves me right, I eventually found an answer on one of the topics on the forum.
However......................once again, the real, undefendable shocker is the total lack of help, advice and support from the very people who took your money when you purchased one of their products.
Why is any help or advice only ever rendered by fellow users who volunteer their knowledge?
Admittedly, there's a half cocked set of instructions "aimed" at helping people install under Windows 8, but I'm gob-smacked at the complete lack of interest AirNav have had in responding to your comments om this matter.
I hope somehow you manage to overcome the problem pal
Rich