Hi: I need to use the stdcall calling convension for a dll that I'm writing. When ever I do this with boost, I get the following errors: ... Creating library d:\Work\Access For Everyone\GHG\TPProductsZW\Debug\TPProductsZW.lib and object d:\Work\Access For Everyone\GHG\TPProductsZW\Debug\TPProductsZW.exp TPProductsZW.obj : error LNK2019: unresolved external symbol "class boost::system::error_category const & __stdcall boost::system::get_system_category(void)" (?get_system_category@system@boost@@YGABVerror_category@12@XZ) referenced in function "void __cdecl boost::system::`dynamic initializer for 'system_category''(void)" (??__Esystem_category@system@boost@@YAXXZ) TPProductsZW.obj : error LNK2019: unresolved external symbol "class boost::system::error_category const & __stdcall boost::system::get_generic_category(void)" (?get_generic_category@system@boost@@YGABVerror_category@12@XZ) referenced in function "void __cdecl boost::system::`dynamic initializer for 'generic_category''(void)" (??__Egeneric_category@system@boost@@YAXXZ) d:\Work\Access For Everyone\GHG\TPProductsZW\Debug\TPProductsZW.dll : fatal error LNK1120: 2 unresolved externals Does anyone know how to solve this issue? I'm building statically, and using visual studio c++ 2008, I'm also using __declspec(dllexport) Regards Sean. Results