Martin, you need to have more faith in yourself.
The registry is not that scary so long as you follow suggestions to the letter.
I used to be apprehensive about dabbling in that dark place but once you've done it a few times, you do get to know where to look the next time.
As for your aircraft download, you more than likely have to add it to the allowed files in defender and your AV software. If you look in the two programs, you should be able to find something like add programs or files to the allowed folder.
Have a look and I will have a look later when I get on the pc.