The solution was for vc7.1 but i have vc7.0 and i got these errors from contructor.h C:\Boost\include\boost-1_31\boost\fsm\detail\constructor.hpp(42): error C2039: 'context_ptr_type' : is not a member of 'operator``global namespace''' C:\Boost\include\boost-1_31\boost\fsm\detail\constructor.hpp(42): error C2825: 'boost::fsm::detail::outer_constructor<ContextList,OutermostContext>::to_construct::context_ptr_type': cannot form a qualified name C:\Boost\include\boost-1_31\boost\fsm\detail\constructor.hpp(42): fatal error C1507: previous user errors and subsequent error recovery halt further compilation _________________________________________________________________ Protect your PC - get McAfee.com VirusScan Online http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963