C:\Pem\simnow_checkouts\simnow_B\PEM>C:\Python25\python.exe setup.py build --compiler=msvc running build running build_ext building 'demo' extension Traceback (most recent call last): File "setup.py", line 20, in <module> ext_modules = [ext_demo]) File "C:\Python25\lib\distutils\core.py", line 151, in setup dist.run_commands() File "C:\Python25\lib\distutils\dist.py", line 974, in run_commands self.run_command(cmd) File "C:\Python25\lib\distutils\dist.py", line 994, in run_command cmd_obj.run() File "C:\Python25\lib\distutils\command\build.py", line 112, in run self.run_command(cmd_name) File "C:\Python25\lib\distutils\cmd.py", line 333, in run_command self.distribution.run_command(command) File "C:\Python25\lib\distutils\dist.py", line 994, in run_command cmd_obj.run() File "C:\Python25\lib\distutils\command\build_ext.py", line 290, in run self.build_extensions() File "C:\Python25\lib\distutils\command\build_ext.py", line 416, in build_extensions self.build_extension(ext) File "C:\Python25\lib\distutils\command\build_ext.py", line 481, in build_extension depends=ext.depends) File "C:\Python25\lib\distutils\msvccompiler.py", line 354, in compile if not self.initialized: self.initialize() File "C:\Python25\lib\distutils\msvccompiler.py", line 264, in initialize self.__paths = self.get_msvc_paths("path") File "C:\Python25\lib\distutils\msvccompiler.py", line 616, in get_msvc_paths % (self.__root, self.__version)) AttributeError: MSVCCompiler instance has no attribute '_MSVCCompiler__root' I did some web searching and read that I can: os.environ['DISTUTILS_USE_SDK'] = "1" os.environ['MSSdk'] = "1" http://docs.python.org/dist/module-distutils.msvccompiler.html C:\Pem\simnow_checkouts\simnow_B\PEM>C:\Python25\python.exe setup.py build --compiler=msvc running build running build_ext building 'demo' extension error: Don't know how to compile demo.C Unfortunately it sounds like I might need to use the "Platform SDK" to compile even my very basic python extension module (just loads a dll and calls one method) (Windows64, python2.5) :-(