Hi, The problem arises when I try to use /bin/Rcmd shlib to create a DLL for external fortran code to do numerical integration from Dr. Alan Genz's website. I tried this yesterday after downloading R-tools, activePerl, mingw and cygwin and reinstalling R. I used the following command c:\"program files"\R\rw2010\bin\Rcmd shlib ranrth.f I got the following error message: In function 'DllMainCRTStartup': d:/src/mingw/build/runtime/../..runtime/dllcrt1.c:67: undefined reference to '_pei386_runtime_relocator' I am a new user, but I searched the R web-site first, and couldn't find this error message. A google search confirmed that it is a cygwin error message, but it was in an exchange between two cygwin developers, and I couldn't figure out what the message means. The only google hits were on the cygwin web-site. The cygwin web-site also said that they would flame any new users who asked stupid questions, and I am hoping you guys are more tolerant. thanks warmly, Marian Ewell