Hello, Rmpi_0.5-4 is not working with MPICH2. I have mpich2-1.0.6 on a windows cluster. R-2.5.1 and Rmpi_0.5-3 is working well. Running R-2.6.0 and Rmpi_0.5-4 on one PC is working! Using more PCs mpi.spawn.Rslaves(nslaves=4) hangs without any error. There is also no message in the mpi.log Any ideas for debugging? I build Rmpi by my self with Rtools: Rcmd build --binary Rmpi_0.5-4\Rmpi It is working well, but there is a warning: "this package has a configure script. It probably needs manual configuration" Are there any problems by this warning? Best Markus -- Dipl.-Tech. Math. Markus Schmidberger Ludwig-Maximilians-Universit?t M?nchen IBE - Institut f?r medizinische Informationsverarbeitung, Biometrie und Epidemiologie Marchioninistr. 15, D-81377 Muenchen URL: http://ibe.web.med.uni-muenchen.de Mail: Markus.Schmidberger [at] ibe.med.uni-muenchen.de