Dear G++ programers: I tried your suggestion ---- eric@eric-laptop:~/cppcookbook$ g++ -I/home/eric/boost1/boost_1_46_1/ example12-1.cpp -lboost_thread-mt /usr/bin/ld: cannot find -lboost_thread-mt collect2: ld returned 1 exit status ------------ can you download my simple c++ creating thread program on my first mailing list in this topic(thread) then base/against boost's 1.46.1 on your g++(mostly on linux) see how to do can make this simple c++ code compile and link thanks a lot in advance, Eric