Installing both MPI implementations on a single system does not typically present a problem. The two implementations are installed in different folders and as such should not conflict with each other.
In order to have both usable, there are some considerations. A binary developed with one implementation cannot be gauranteed to work with the other implementation. As such, the user and/or the developer should always be aware of which implementation is being used. The Intel® MPI Library can be selected by running the batch file:
This will set the %PATH%, %LIB%, and %INCLUDE% environment variable to find the Intel® MPI Library, as well as setting additional variables used by the Intel® MPI Library. In order to use the Microsoft* MPI implementation, you can either set your environment variables to find its installation folder first, or use the full path when running.