Hi, I have problem installing the MPI 64x application on my new PC with win7 OS. I was able to stall it to get it running on two PC previously. I had follow the exact steps as in the instruction. It indicated successful installation. Not sure why it is not running this time. The error msg is shown below after I run the example test. Sam ===================================================== c:\nm72gf64\run>nmfe72 foce_parallel.ctl foce_parallel.res -parafile=mpiwini2.pnm doing nmtran WARNINGS AND ERRORS (IF ANY) FOR PROBLEM 1 (WARNING 2) NM-TRAN INFERS THAT THE DATA ARE POPULATION. CREATING MUMODEL ROUTINE... 1 file(s) copied. recompiling certain components. starting wait ending wait Exiting lpreddo Finished compiling fsubs USING PARALLEL PROFILE mpiwini2.pnm MPI TRANSFER TYPE SELECTED Completed call to gfcompile.bat Starting MPI version of nonmem execution ... Error while connecting to host, No connection could be made because the target machine actively refused it. (10061) Connect on sock (host=localhost, port=8676) failed, exhaused all end points Unable to connect to 'localhost:8676', sock error: Error = -1 Could Not Find c:\nm72gf64\run\output c:\nm72gf64\run>