I've encountered some issues with running my app using mpich2 1.4.1 on windows. Win7 64, 32bit app built with vc++2010 express with 32bit mpich2 binary install of a couple days ago. Different version of OpenGL are found when I invoke the program with and without mpiexec. with mpiexec the wrong one is used seriously crippling my rendering capabilities. This system has two graphics devices, an ati radeon and intel hd4000 bundled with the cpu. It is possible to hot switch between them, although to simplify things I've disabled the ati for now and am using hd4000. All the OpenGL libraries are system installed libraries (not in current dir or PATH) so I would have thought that when run under mpich they would be located the same as when not. Any idea why system library search is different with mpich and what may be done about it? Thanks Burlen