Hi, when trying to compile boost.python using python 2.5.2 (amd64) and Visual Studio 9 the following linker errors occur. I found out that the symbols are really missing from the python25.lib while they are present in the 32bit version. So i think this can be a problem of python. When searching the web i found that this problem is known but no action are taken till now. The python 2.6 rc2 also has the same problem. Here the errors (shortened): ...updating 5 targets... msvc.link.dll e:\devel\_ext\boost_out_64\out\boost\bin.v2\libs\python\build\msvc-9.0_64\release\threading-multi\boost_python-vc90-mt-1_36.dll Creating library e:\devel\_ext\boost_out_64\out\boost\bin.v2\libs\python\build\msvc-9.0_64\release\threading-multi\boost_python-vc90-mt-1_36.lib an d object e:\devel\_ext\boost_out_64\out\boost\bin.v2\libs\python\build\msvc-9.0_64\release\threading-multi\boost_python-vc90-mt-1_36.exp function.obj : error LNK2001: unresolved external symbol __imp__PyErr_Format numeric.obj : error LNK2019: unresolved external symbol __imp__PyErr_Format referenced in function "void __cdecl boost::python::numeric::`anonymous na mespace'::throw_load_failure(void)" (?throw_load_failure@?A0x4c737783@numeric@python@boost@@YAXXZ) from_python.obj : error LNK2001: unresolved external symbol __imp__PyErr_Format registry.obj : error LNK2001: unresolved external symbol __imp__PyErr_Format class.obj : error LNK2001: unresolved external symbol __imp__PyErr_Format numeric.obj : error LNK2019: unresolved external symbol __imp__PyExc_ImportError referenced in function "void __cdecl boost::python::numeric::`anonymo us namespace'::throw_load_failure(void)" (?throw_load_failure@?A0x4c737783@numeric@python@boost@@YAXXZ) enum.obj : error LNK2001: unresolved external symbol __imp__PyEval_CallFunction class.obj : error LNK2001: unresolved external symbol __imp__PyEval_CallFunction Regards -chris -- Christopher Lux | | Bauhaus-Universität Weimar | faculty of media - virtual reality systems group