Fix ipwin does not build 64-bit application in windows 7

windows/ipwin/ipwin/build.bat

@@ -4,8 +4,9 @@ SETLOCAL
 SET VCVARSALL="C:\Program Files\Microsoft Visual Studio 9.0\VC\vcvarsall.bat"
 SET SETENV="C:\Program Files\Microsoft SDKs\Windows\v7.0\Bin\SetEnv.cmd"
 
-IF /I "%PROCESSOR_ARCHITECTURE%" == "x86" GOTO ARCH_X86 
+IF /I "%PROCESSOR_ARCHITEW6432%" == "AMD64" GOTO ARCH_AMD64
 IF /I "%PROCESSOR_ARCHITECTURE%" == "AMD64" GOTO ARCH_AMD64
+IF /I "%PROCESSOR_ARCHITECTURE%" == "x86" GOTO ARCH_X86
 
 ECHO.
 ECHO Failed to build, unknown architecture: %PROCESSOR_ARCHITECTURE%