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/x64.vsprops b/PCbuild9/x64.vsprops
index acc3325..c7eabbe 100644
--- a/PCbuild9/x64.vsprops
+++ b/PCbuild9/x64.vsprops
@@ -9,6 +9,7 @@
 	<Tool
 		Name="VCCLCompilerTool"
 		AdditionalOptions="/USECL:MS_OPTERON /GS-"
+		PreprocessorDefinitions="_WIN64;_M_X64"
 	/>
 	<Tool
 		Name="VCLinkerTool"