diff --git a/include/boost/config/compiler/comeau.hpp b/include/boost/config/compiler/comeau.hpp
index d2dd2dc0..4d5eb796 100644
--- a/include/boost/config/compiler/comeau.hpp
+++ b/include/boost/config/compiler/comeau.hpp
@@ -11,7 +11,7 @@
 
 #if (__COMO_VERSION__ <= 4245) || !defined(BOOST_STRICT_CONFIG)
 #  define BOOST_FUNCTION_USE_VIRTUAL_FUNCTIONS
-#  if defined(_MSC_VER) && _MSC_VER <= 1200
+#  if defined(_MSC_VER) && _MSC_VER <= 1300
 #     define BOOST_NO_STDC_NAMESPACE
 #     define BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
 #     define BOOST_NO_SWPRINTF
diff --git a/include/boost/config/platform/win32.hpp b/include/boost/config/platform/win32.hpp
index cdad4c93..1c7ac59e 100644
--- a/include/boost/config/platform/win32.hpp
+++ b/include/boost/config/platform/win32.hpp
@@ -24,7 +24,13 @@
 #  define BOOST_NO_SWPRINTF
 #endif
 
-#define BOOST_HAS_WINTHREADS
+//
+// Win32 will normally be using native Win32 threads,
+// but there is a pthread library avaliable as an option:
+//
+#ifndef BOOST_HAS_PTHREADS
+#  define BOOST_HAS_WINTHREADS
+#endif
 
 // WEK: Added
 #define BOOST_HAS_FTIME
diff --git a/include/boost/config/posix_features.hpp b/include/boost/config/posix_features.hpp
index e8e23912..7a4a4591 100644
--- a/include/boost/config/posix_features.hpp
+++ b/include/boost/config/posix_features.hpp
@@ -26,7 +26,7 @@
       // Strictly speaking this may catch platforms with a
       // non-functioning stub <pthreads.h>, but such occurrences should
       // occur very rarely if at all.
-#     if defined(_POSIX_THREADS) && (_POSIX_THREADS+0 >= 0)
+#     if defined(_POSIX_THREADS) && (_POSIX_THREADS+0 >= 0) && !defined(BOOST_HAS_WINTHREADS)
 #        define BOOST_HAS_PTHREADS
 #     endif
 
diff --git a/include/boost/config/suffix.hpp b/include/boost/config/suffix.hpp
index c52593cf..b8596b74 100644
--- a/include/boost/config/suffix.hpp
+++ b/include/boost/config/suffix.hpp
@@ -146,6 +146,14 @@
 #  undef BOOST_HAS_THREADS
 #endif
 
+//
+// Turn threading support off if we don't recognise the threading API:
+//
+#if defined(BOOST_HAS_THREADS) && !defined(BOOST_HAS_PTHREADS)\
+      && !defined(BOOST_HAS_WINTHREADS) && !defined(BOOST_HAS_BETHREADS)
+#  undef BOOST_HAS_THREADS
+#endif
+
 //
 // If the compiler claims to be C99 conformant, then it had better
 // have a <stdint.h>: