The Basel installer allows only one installation on the drive where the P3D sceneries are stored.
That's because you chose to install there. By default, the FSDT folder is in C:\Program Files (x86)\Addon Manager. There is a reason why we choose to use a "neutral" folder, and it's precisely to support multiple simulators without duplicating any files. With "multiple simulators", it means FSX, FSX:SE, P3D4, P3D5 and MSFS 2020.
It would need a way to select a different folder during installation. Because the sizes of the drives are limited.
You surely can, but it will never fit your logic of keeping the P3D stuff on one drive and the MSFS stuff on another one, which is really not giving you any real benefit. Quite the opposite, instead, a possible advantage of using two drives, is that you can speed up the loading process, by taking advantage of the fact that a single drive will never be able to saturate the PCI bus so, instead of separating by simulators ( you never use two simulators at the time ), you should do this instead:
- Install the *core* MSFS on its default folder and the CONTENT ( the big download ) on a *different* drive.
- Install P3D on a drive, even the same as the *core* MSFS, and all P3D add-on on a *different* drive.
That's the solution that is best for performances ( assuming all your drives are the same speed, because they are not, you should install the biggest files on the faster drive ) and, of course, our installer structure is designed to help with that.
If you want to change the FSDT default folder, you must:
- Uninstall ALL FSDT products ( both for P3D and MSFS )
- Reply YES to the question "Do you want to remove the Addon Manager" ? This will allow you to freely choose the folder again.
- Reinstall all FSDT product. The first one you install will allow you to choose a folder, the others will automatically go there. You can install everywhere, as long all FSDT products stays together, so they can be updated in a single go ( if they weren't, you would have to start the Live Update twice every time ), and there's no wasted space, even if they share files between all the different supported simulators.