Hello, I have compilation problem when trying to just #include <boost/asio.hpp>: /src/timer.o: In function `ZNK5boost16exception_detail15exception_cloneINS0_19error_info_injectorINS_6system12system_errorEEEE7add_refEv': C:/Dev/MessageThreads/Debug/../src/timer.cpp:(.text$_ZN5boost4asio6detail12winsock_initILi2ELi0EE7do_initD1Ev[boost::asio::detail::winsock_init<2, 0>::do_init::~do_init()]+0x7): undefined reference to `WSACleanup@0' C:/Dev/MessageThreads/Debug/../src/timer.cpp:(.text$_ZN5boost4asio6detail12winsock_initILi2ELi0EE7do_initC1Ev[boost::asio::detail::winsock_init<2, 0>::do_init::do_init()]+0x1f): undefined reference to `WSAStartup@8' collect2: ld returned 1 exit status I linked boost system boost_system-mgw34-mt-d-1_36 in Eclipse (MinGW C++ linker). Can someone please tell me what is wrong? Thanks a lot! Gali.