I try to use boost 1.51 for my vc++ 64 bit application on windows 7 enterprise. In short, if I set config to 32 bit, everything is OK. I mean build successfully. But if I changed to 64 bit, I get build error. I am sure I include the 64 bit header and the lib path is 64 bit lib. My test application is win32 console application. The error I got: Error 1 error LNK2019: unresolved external symbol main referenced in function __tmainCRTStartup D:\Temp\test\test\MSVCRTD.lib(crtexe.obj) test My test.cpp: #define BOOST_TEST_MAIN #include <boost/test/unit_test.hpp> Why 32 bit build and 64 bit would not? The library I used is from www.boostpro.com. -- View this message in context: http://boost.2283326.n4.nabble.com/unit-test-on-vc-64-bit-application-tp4645... Sent from the Boost - Users mailing list archive at Nabble.com.