Interesting problem: sometimes you want to build extensions with a newer version of the compiler than the python interpreter was built with. Sometimes you want to be smarter than the machine, so it would be very handy to have some manual override in msvccompiler.py, in get_build_version(), perhaps something like: if os.environ.has_key('MSVC_VERSION'): return float(os.environ['MSVC_VERSION']) This allows you as the smart developer to force the compilation of the extension to use whatever compiler version you set your environment to; if you don't set it, the system does what it does now. Thoughts? -Ivan