I don't use this.  Instead, I put Simply Fortran here:
   "C:\Program Files (x86)\Fortran\SF".

I also map a virtual drive, called F:\, to this path, but that is not relevant to this posting.

I've noticed that, when installing a new version of SF, the installer always offers only the default path.
This is very inconvenient.  Would it be possible for the installer to read the current path from the ENVIRONMENT variable, 'PATH', and to offer that as the install suggestion, only using the default path when it doesn't find a pre-installed path?

I note also that, when occasionally re-installing an existing version, the installer doesn't prompt for a path, and offers only a REPAIR option.  When one uses this, the installer appears not to find the path in which SF is actually installed, but instead to assume it will be in the default path.  In not finding it there, the installer seems to "repair" SF by placing all the files needed in the default file location.  I am not 100% certain that this is what happens but I think it is.  If so, I am thinking that this might also be something to look into in due course.
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John