So Everyone knows,How to fix the Garmin GTN 750 reinstall.... When I originally down loaded I did not have to create an account with flight1.com. Now you have to because you cannot use the "Certificate Number" any more, you received when you purchased GTN 750. Now you have to create a F1 account with using the same email address you used when you originally purchased it. It is tied to your email address. Then it kept taking me to download GarminTrainerSetup2500.exe and it came up with "File not Found (404)". So I unchecked the box on the install called download "GarmenTrainerSetup" and installed just the X-Plane setup. When you open x-plane it just came up with a blank GTN 750 window, nothing else. So I went back to the install setup screen again and it gave you an option when you read one of the read me files to download a previous version manually of the "GarmenTrainerSetup" and install it separately of GarminTrainerSetup (It was the 3rd one down on the page in my situation). So I did this and reinstalled the X-Plane setup file and it worked in X-Plane perfectly. I noticed some of the features in the Garmin did not show for example taxiways at YBBN-Brisbane. So I went through the same install process again and it gave me a option to upgrade, so I did and the taxiways showed up. Now everything is working perfectly.
I hope this helps everyone. I notice a few people on the forum had the same or similar problems.