I am attempting to build boost, first I set some environment vars (some may not be useful anymore, but I still set them): set BZIP2_SOURCE=G:\SDKs\boost\bzip2-1.0.4 set ZLIB_SOURCE=G:\SDKs\boost\zlib-1.2.3 set HAVE_ICU=1 set ICU_PATH=R:\SDKs\icu\icu set EXPAT_INCLUDE=G:\SDKs\expat\expat_cvs\expat\lib set EXPAT_LIBPATH=G:\SDKs\expat\expat_cvs\expat\win32\bin\release I then call: bootstrap.bat bjam --build-type=complete --toolset=msvc-8.0 --without-mpi --without-python --prefix=R:/SDKs/boost/built_head --build-dir=R:/SDKs/boost/build_head define=_CRT_NONSTDC_NO_DEPRECATE define=_CRT_SECURE_NO_DEPRECATE define=_SECURE_SCL=0 define=_SCL_SECURE_NO_DEPRECATE define=_HAS_ITERATOR_DEBUGGING=0 install>..\build-HEAD.log And my build-HEAD.log contains: Note: Building Boost.Regex with Unicode/ICU support enabled Using ICU in R:\SDKs\icu\icu/include warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user_config.jam error: link=shared together with runtime-link=static is not allowed error: such property combination is either impossible error: or too dangerious to be of any use I have never seen those last three errors, and other then the bootstrap my commands have not changed in many many versions. What is causing them?