Hello,
Most likely, both products create a file association upon installtion.
Unfortunately, I'm afraid there isn't any way in which you can distinguish the two - at least not one that I'm aware of.
This happens with other products as well. For instance, take the default Notepad and Notepad++. Both are meant to open .txt files, but only one can be the default application at a time. If the Notepad is the default applicaiton, then you can open the .txt files by right clicking on the file --> "Open with Notepad++".
You can do the same with your Advanced Installer projects. You can right click on it --> "Open with" and select Advanced Installer.
Similarly, you can open Advanced Installer and use the "Open" --> "Open project" function.
Hope this helps!
Best regards,
Catalin