MPI-3 is recommended for Fortran across computing platforms, including Windows.

For native x86 (Intel / AMD CPU) binaries, currently only free Intel oneAPI has MPI-3 for Fortran.

Windows Subsystem for Linux can use OpenMPI or MPICH to access MPI-3 for Fortran. For Windows ARM CPU users, Windows Subsystem for Linux is currently the only option for MPI-3 in Fortran.