Hi, I installed Boost 1.4.47 on a Linux x86_64 server with gcc 4.4.4. When I try to make a simulator which uses Boost libraries I get the following error message: /home/abanaiya/local//include/boost/system/error_code.hpp:316: note: candidates are: boost::system::error_code::error_code(int&, const boost::system::error_category&) /home/abanaiya/local//include/boost/system/error_code.hpp:315: note: boost::system::error_code::error_code() /home/abanaiya/local//include/boost/system/error_code.hpp:311: note: boost::system::error_code::error_code(const boost::system::error_code&) ../../src/boost.task-0.4.2/boost/task/detail/bind_processor_linux.hpp: In function âvoid boost::this_thread::bind_to_processor(unsigned int)â: ../../src/boost.task-0.4.2/boost/task/detail/bind_processor_linux.hpp:41: error: no matching function for call to âboost::system::error_code::error_code(int&, const boost::system::error_category& (&)())â /home/abanaiya/local//include/boost/system/error_code.hpp:316: note: candidates are: boost::system::error_code::error_code(int&, const boost::system::error_category&) /home/abanaiya/local//include/boost/system/error_code.hpp:315: note: boost::system::error_code::error_code() /home/abanaiya/local//include/boost/system/error_code.hpp:311: note: boost::system::error_code::error_code(const boost::system::error_code&) ../../src/boost.task-0.4.2/boost/task/detail/bind_processor_linux.hpp: In function âvoid boost::this_thread::bind_to_any_processor()â: ../../src/boost.task-0.4.2/boost/task/detail/bind_processor_linux.hpp:59: error: no matching function for call to âboost::system::error_code::error_code(int&, const boost::system::error_category& (&)())â /home/abanaiya/local//include/boost/system/error_code.hpp:316: note: candidates are: boost::system::error_code::error_code(int&, const boost::system::error_category&) /home/abanaiya/local//include/boost/system/error_code.hpp:315: note: boost::system::error_code::error_code() /home/abanaiya/local//include/boost/system/error_code.hpp:311: note: boost::system::error_code::error_code(const boost::system::error_code&) /home/abanaiya/local//include/boost/system/error_code.hpp: At global scope: /home/abanaiya/local//include/boost/system/error_code.hpp:214: warning: âboost::system::posix_categoryâ defined but not used /home/abanaiya/local//include/boost/system/error_code.hpp:215: warning: âboost::system::errno_ecatâ defined but not used /home/abanaiya/local//include/boost/system/error_code.hpp:216: warning: âboost::system::native_ecatâ defined but not used make[2]: *** [sim.o] Error 1 make[1]: *** [all-recursive] Error 1 make: *** [all-recursive] Error 1 I also received the following error that I removed it by disabling the corresponded line at api_config.hpp file. /home/abanaiya/local//include/boost/system/api_config.hpp:28:5: error: #error user defined BOOST_POSIX_API or BOOST_WINDOWS_API not supported I also tried version 1.4.42 and got the same error. Would you please let me know hot to resolve it. I run the following command to install the Boost: ./bjam --prefix=$HOME/local install Thanks, Abbas