May you tell me if and where are files/directory that have to be deleted in addition to the standard uninstalling procedure? Including instructions inside P3D V4 in the xlm, dll files o others to get a complete unpresence of GSX in my computer.
If you reply YES to the question "Do you want to remove the Addon Manager ?", it will entirely remove the software. The only thing that will not remove, are your own customization files for airports and airplanes, located here:
%APPDATA%\Virtuali
So, you should decide, depending how many customizations you made, if you want to remove that folder too. Or, possibly, make a backup of it, first.