With David's guidance, was able to get pman running well. It provides a good example to go by for building cluster code for Windows systems. For the next step in my process, I created a simple cluster program and was able to get it to work well. However, a more complicated program based on that build approach did not come out well. This program works well on our Linux system. It is generic C++ code that makes no special use of the operating system or memory arrangement. When built under Windows it will run fine on a single node when mpiexec is not invoked. However, the following error message arrives when mpiexec is invoked: C:\temp\MPI>C:\Program_Files\MPICH2\bin\mpiexec -pwdfile Options.txt -exitcodes -hosts 1 raethserver testpad_sansmfc rank: node: exit code 0: raethserver: -1073741515 Is there a place where exit codes are documented?