a program like

#include "boost/network/protocol/http.hpp"
typedef network::http::basic_client<tags::http_keepalive_8bit_udp_resolve, 1, 1> http_client;
http_client();

makes an error

C:\work\boost\boost/asio/ssl/detail/openssl_types.hpp(23) : fatal error C1083: Cannot open include file: 'openssl/conf.h': No such file or directory

if openssl is installed. this example shouldn't need OpenSSL.