I have been using VS Enterprise 2015. I have downloaded VS 2017 Community. Do I need to uninstall FORTRAN and then re-install it to get the 2017 Community VS to recognize it?
You don't have to uninstall. You do have to do a "Change/Modify" on Intel Parallel Studio XE and select VS2017 when it asks you which VS versions you want to integrate with. This assumes you are using a version of Parallel Studio XE that supports VS2017.