diff --git a/Modules/errnomodule.c b/Modules/errnomodule.c
--- a/Modules/errnomodule.c
+++ b/Modules/errnomodule.c
@@ -7,6 +7,33 @@
 #ifdef MS_WINDOWS
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
+/* The following constants were added to errno.h in VS2010 but have
+   preferred WSA equivalents. */
+#undef EADDRINUSE
+#undef EADDRNOTAVAIL
+#undef EAFNOSUPPORT
+#undef EALREADY
+#undef ECONNABORTED
+#undef ECONNREFUSED
+#undef ECONNRESET
+#undef EDESTADDRREQ
+#undef EHOSTUNREACH
+#undef EINPROGRESS
+#undef EISCONN
+#undef ELOOP
+#undef EMSGSIZE
+#undef ENETDOWN
+#undef ENETRESET
+#undef ENETUNREACH
+#undef ENOBUFS
+#undef ENOPROTOOPT
+#undef ENOTCONN
+#undef ENOTSOCK
+#undef EOPNOTSUPP
+#undef EPROTONOSUPPORT
+#undef EPROTOTYPE
+#undef ETIMEDOUT
+#undef EWOULDBLOCK
 #endif
 
 /*
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -2317,6 +2317,34 @@
 
 #ifdef MS_WINDOWS
 #include <Winsock2.h>
+/* The following constants were added to errno.h in VS2010 but have
+   preferred WSA equivalents. */
+#undef EADDRINUSE
+#undef EADDRNOTAVAIL
+#undef EAFNOSUPPORT
+#undef EALREADY
+#undef ECONNABORTED
+#undef ECONNREFUSED
+#undef ECONNRESET
+#undef EDESTADDRREQ
+#undef EHOSTUNREACH
+#undef EINPROGRESS
+#undef EISCONN
+#undef ELOOP
+#undef EMSGSIZE
+#undef ENETDOWN
+#undef ENETRESET
+#undef ENETUNREACH
+#undef ENOBUFS
+#undef ENOPROTOOPT
+#undef ENOTCONN
+#undef ENOTSOCK
+#undef EOPNOTSUPP
+#undef EPROTONOSUPPORT
+#undef EPROTOTYPE
+#undef ETIMEDOUT
+#undef EWOULDBLOCK
+
 #if defined(WSAEALREADY) && !defined(EALREADY)
 #define EALREADY WSAEALREADY
 #endif
diff --git a/PC/msvcrtmodule.c b/PC/msvcrtmodule.c
--- a/PC/msvcrtmodule.c
+++ b/PC/msvcrtmodule.c
@@ -27,6 +27,8 @@
 #ifdef _MSC_VER
 #if _MSC_VER >= 1500 && _MSC_VER < 1600
 #include <crtassem.h>
+#elif _MSC_VER >= 1600
+#include <crtversion.h>
 #endif
 #endif
 
@@ -464,7 +466,7 @@
 PyInit_msvcrt(void)
 {
     int st;
-    PyObject *d;
+    PyObject *d, *version;
     PyObject *m = PyModule_Create(&msvcrtmodule);
     if (m == NULL)
         return NULL;
@@ -494,6 +496,9 @@
 #endif
 
     /* constants for the crt versions */
+    /* TODO-BC: the following 3 are from VS2008, may want to remove? */
+    /* XXX-BC: I was unable to find VS2010 replacements for TOKEN and PREFIX
+               constants...not sure what to do with them. */
 #ifdef _VC_ASSEMBLY_PUBLICKEYTOKEN
     st = PyModule_AddStringConstant(m, "VC_ASSEMBLY_PUBLICKEYTOKEN",
                                     _VC_ASSEMBLY_PUBLICKEYTOKEN);
@@ -510,5 +515,15 @@
     if (st < 0) return NULL;
 #endif
 
+    /* constants for the 2010 crt versions */
+#if defined(_VC_CRT_MAJOR_VERSION) && defined (_VC_CRT_MINOR_VERSION) && defined(_VC_CRT_BUILD_VERSION) && defined(_VC_CRT_RBUILD_VERSION)
+    version = PyUnicode_FromFormat("%d.%d.%d.%d", _VC_CRT_MAJOR_VERSION,
+                                                  _VC_CRT_MINOR_VERSION,
+                                                  _VC_CRT_BUILD_VERSION,
+                                                  _VC_CRT_RBUILD_VERSION);
+    st = PyModule_AddObject(m, "CRT_ASSEMBLY_VERSION", version);
+    if (st < 0) return NULL;
+#endif
+
     return m;
 }