I have build boost libraries with command line bjam --toolset=msvc --user-config=config32.jam --stagedir=. debug-symbols=on stage File config32.jam is: using msvc : 8.0 : : <cxxflags>"-wd4996 -wd4103 -Zp4" <define>_CRT_SECURE_NO_DEPRECATE <define>_CRT_NONSTDC_NO_DEPRECATE <define>_SECURE_SCL=0 <define>BOOST_SPIRIT_THREADSAFE <define>BOOST_THREAD_USE_DLL <define>BOOST_THREAD_BUILD_DLL ; The resulting libboost_program_options-vc80-mt-1_34.lib has size 7,420,264 bytes and my program, builded with /D "_CRT_SECURE_NO_DEPRECATE" /D "_CRT_NONSTDC_NO_DEPRECATE" /D "_SECURE_SCL=0" /D "BOOST_THREAD_USE_DLL", crashes. When I changed config32.jam to using msvc : 8.0 : : <cxxflags>"-wd4996 -wd4103 -Zp4 -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE -D_SECURE_SCL=0 -DBOOST_SPIRIT_THREADSAFE -DBOOST_THREAD_USE_DLL -DBOOST_THREAD_BUILD_DLL " ; The resulting libboost_program_options-vc80-mt-1_34.lib size is 7,233,568 bytes and my program works well. This looks like <define> in config file sometimes has no effect. Furthermore, program options library is alignment-sensitive.