Premier and Platinum Collection includes aircrafts designed for a particular version of Microsoft Flight Simulator: FSX, FS2004, FS2, FS2000, CFS2, FS98 or CFS1. Each aircraft is specifically identifed as to which version with which it can be used.
When you run the installation, the installation program (Installshield) asks you to choose the Destination Directory. If you do not choose the proper folder (where your version of FS or CFS is located), then the aircraft will not be usable. Therefore during installation, please be sure to choose your main FS folder or your main CFS folder as the destination directory.