Hello, I install and test boost on my computer since two weeks. And I have much problems. Actually I test random with the code indicated on http://www.boost.org/libs/random/index.html The code is #include <iostream> #include int main () { boost::mt19937 rng; // produces randomness out of thin air // see pseudo-random number generators boost::uniform_int<> six(1,6); // distribution that maps to 1..6 // see random number distributions boost::variate_generator > die(rng, six); // glues randomness with mapping int x = die(); // simulate rolling a die } More simple, there is not. And, the error messages on intel c++ 8 are : Compiling... C:\BOOST_1_31_0\boost/integer_traits.hpp(129): error: class "boost::integer_traits" has already been defined class integer_traits<unsigned short> ^ compilation aborted for D:\X Mes Documents X\Mes Programmes\VisualC++ 6\random boost 1\random-1.cpp (code 2) Error executing cl.exe. random boost 1.exe - 1 error(s), 0 warning(s) Would anybody have already seen it? errors on template class who have multiples definitions on the header "integer_traits.hpp". The compiler don't accept surcharge of template class. Perhaps there is an option for the compiler. What do you think about this ? After this problem, I test with msvc++6 sp5 + service pack processor 5 and... Compiling... random-1.cpp C:\BOOST_1_31_0\boost/random/uniform_01.hpp(34) : fatal error C1001: INTERNAL COMPILER ERROR (compiler file 'msc1.cpp', line 1794) Please choose the Technical Support command on the Visual C++ Help menu, or open the Technical Support help file for more information Error executing cl.exe. random boost 1.exe - 1 error(s), 1 warning(s) it gives me an error fatal with no information on Technical Support of VC6. I ask me if the problem is linked at the service pack 5 for msvc and service pack 5 for processor ( http://msdn.microsoft.com/vstudio/downloads/tools/ppack/download.aspx ),I have install. Someone have installed this pack ? Thanks for your responses. heinquoi