I've bulked up my system enough that I can run Prepar3d v2.5 and v 3.1 on the same machine (though not at the same time ). I already installed the 777 and 737 NGX in 3.1. Now I am trying to install in 2.5 and all I get is a dialog asking if I want to modify, repair or replace my existing installation. The different versions of P3D are installed on separate drives. The reason I want to install on both versions is I have other add-ins (mostly scenery) that only work in 2.5. When (and if) all my add-ins catch up to 3.1 then I'll ditch the 2.5 but for now I need the older version for some flights.
Is there a way to install the PMDG aircraft in both versions of P3D?