https://svn.boost.org/trac10/ticket/9120 <p> In the system_error_category::message(), the FormatMessageA(...,MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),...) is used to create error messages. Unfortunately, this code can produce non-english error messages in the ANSI encoding. </p> <p> According to the <a href="http://www.boost.org/community/error_handling.html">http://www.boost.org/community/error_handling.html</a>, "internationalization is beyond the scope of the exception class author". So, I think that it would be better to use MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT) here. </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/9120 Trac 1.4.3