Ansys 13---> HP-MPI or Intel-MPI
 

HI All,
I have installed the ANSYS 13. After the installation, i want to install "MPI for FLUENT Parallel", .
I want to know that which MPI should I install, Intle-MPI or HP-MPI???
I read the Anysy Help Manual, but i did not understand my answer.
So could anyone please tell me about this question?

Plus, for each of HPMPI and Intel_MPI there is an installation instruction , and at the end of each instruction ( for example, HPMPI version) there are two steps that I dont know how to do them.
When the installation is complete, add %MPI_ROOT%\bin to your System PATH environment variable.
To cache your Windows password, open a Command Prompt window and run:
"%AWP_ROOT130%\ansys\hpmpi\sethpmpipassword" .

I highly appreciate in advance,