I have just bought a Dakota.
The install failed at 'GNS Trainer\CHGT..' .when I was left with a black screen and a blinking 'C'.
When I tried to run it in SP2, I got "Can't find the Garmin Trainer 430 program. Check registry or reinstall."
I know nothing about the registry, and there seemed no point in a reinstall. .
I have tried your recommendation of going into C:Documents and settings...GnsTrainer\Inst 430. Selecting the option does not, as you say, automatically start the Trainer installer. And double-clicking on the exe icon has absolutely no effect.
So it does not, as you claim, solve all issues.
In all my years of simming, I have never before been so totally let down by a payware aircraft - or, indeed, a freeware aircraft.
Please let me know how to secure a refund.