Index: boost/config/compiler/visualc.hpp
===================================================================
--- boost/config/compiler/visualc.hpp	(revision 85866)
+++ boost/config/compiler/visualc.hpp	(working copy)
@@ -100,6 +100,9 @@
 #  define BOOST_HAS_THREADEX
 #  define BOOST_HAS_GETSYSTEMTIMEASFILETIME
 #endif
+#ifdef BOOST_FOR_WINRT
+#undef BOOST_HAS_THREADEX
+#endif
 
 //
 // check for exception handling support: