The macros _WIN32, _WIN64 and _M_X64 are defined by the compiler. The VS 2008 IDE doesn't know about (some) of the macros and can display wrong information. In my case a section #ifdef _WIN64 was grayed out although the platform was x64. I've added the macros to pyproject.vsprops and x64.vsprops.
I've also added a paragraph about the property files to the readme and fixed the order of pyupdate > pyinstrument.
diff --git a/PCbuild9/readme.txt b/PCbuild9/readme.txt
index 791edb2..fd3967a 100644
--- a/PCbuild9/readme.txt
+++ b/PCbuild9/readme.txt
@@ -293,6 +293,31 @@
change the "Runtime Library" from "Multi-threaded DLL (/MD)" to
"Multi-threaded (/MT)".
+Visual Studio properties
+------------------------
+
+The PCbuild9 solution makes heavy use of Visual Studio property files
+(*.vsprops). The properties can be viewed and altered in the Property
+Manager (View -> Other Windows -> Property Manager).
+
+ * debug (debug macros)
+ * pginstrument (PGO)
+ * pgupdate (PGO)
+ +-- pginstrument
+ * pyd (python extension, release build)
+ +-- release
+ +-- pyproject
+ * pyd_d (python extension, debug build)
+ +-- debug
+ +-- pyproject
+ * pyproject (base settings for all projects)
+ * release (release macros)
+ * x64 (AMD64 / x64 platform specific settings)
+
+The pyproject propertyfile defines _WIN32 and x64 defines _WIN64 and _M_X64
+although the macros are set by the compiler, too. The GUI doesn't always know
+about the macros and confuse the user with false information.
+
YOUR OWN EXTENSION DLLs
-----------------------
If you want to create your own extension module DLL, there's an example