Hi All: I develop a service of windows for launching MPI app. The service launches the following command via CreateProcess(...) mpiexec.exe -localonly -n 4 MPIApp.exe My test machine is Windows XP Professional SP2 64bit The version of Intel MPI I use is 4.0 update 3 And I got the error message: init command received but no process group structure found to match it: pg <> [0] PMI_Init failed: FAIL - init command received but no process group structure fount to match it. Fatal error in MPI_Init: Other MPI error, error stack: MPIR_Init_thread(645): Initialization failed MPID_Init(134).......: channel initialization failed MPID_Init(430).......: PMI_Init returned -1 init command received but no process group structure found to match it: pg <> [0] PMI_Init failed: FAIL - init command received but no process group structure fount to match it. Fatal error in MPI_Init: Other MPI error, error stack: MPIR_Init_thread(645): Initialization failed MPID_Init(134).......: channel initialization failed MPID_Init(430).......: PMI_Init returned -1 init command received but no process group structure found to match it: pg <> [0] PMI_Init failed: FAIL - init command received but no process group structure fount to match it. Fatal error in MPI_Init: Other MPI error, error stack: MPIR_Init_thread(645): Initialization failed MPID_Init(134).......: channel initialization failed MPID_Init(430).......: PMI_Init returned -1 init command received but no process group structure found to match it: pg <> [0] PMI_Init failed: FAIL - init command received but no process group structure fount to match it. Fatal error in MPI_Init: Other MPI error, error stack: MPIR_Init_thread(645): Initialization failed MPID_Init(134).......: channel initialization failed MPID_Init(430).......: PMI_Init returned -1 But if I use regular user to open a cmd.exe and run the command line above, everything is ok. I open a cmd.exe with SYSTEM account privilege and run the command line above, and I got the same error message. The way to start a cmd.exe with SYSTEM account privilege on Windows XP is as the followings: (1)open a cmd.exe (2)type at 16:31 /interactive cmd.exe (3)Now at time 16:31, a new cmd.exe will pop up with SYSTEM account privilege (4)run commandline: mpiexec.exe -localonly -n 4 MPIApp.exe regards, Seifer