Hi, I installed Boost 1.47 using Windows Installer. I have Visual C++ 2010 Express installed and I installed Platform SDK for 2003 and Windows Driver Kit, that give me MFC/ATL, etc., separately. However, I have to set the directories in each project before I build anything otherwise the VC++ 2010 picks up the Windows SDK 7.0 that gets installed by default by Visual C++ 2010 Express. So Boost installer, I suspect, too picked up the wrong SDK, Windows SDK 7, directories instead of the those of the platform SDK. I suspect so because upon including ASIO header and just getting an IP Address string, I get build warnings like these: Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately. For example: - add -D_WIN32_WINNT=0x0501 to the compiler command line; or - add _WIN32_WINNT=0x0501 to your project's Preprocessor Definitions. Assuming _WIN32_WINNT=0x0501 (i.e. Windows XP target). File0001.cpp Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately. For example: - add -D_WIN32_WINNT=0x0501 to the compiler command line; or - add _WIN32_WINNT=0x0501 to your project's Preprocessor Definitions. Assuming _WIN32_WINNT=0x0501 (i.e. Windows XP target). File0002.cpp Second_test.cpp Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately. For example: - add -D_WIN32_WINNT=0x0501 to the compiler command line; or - add _WIN32_WINNT=0x0501 to your project's Preprocessor Definitions. Assuming _WIN32_WINNT=0x0501 (i.e. Windows XP target). Any idea how I can fix this? Best, Asif