This looks like a spaces in path problem: your problematic path mixes short windows names and long windows names and is not in quotes ("...") c:\docume~1\wd15\locals~1\temp\wd15\python25_intermediate\compiler_08edc7e348e1c33f63a33ab500aef08e\Release\program files\pythonxy\python\lib\site-packages\scipy\weave\scxx\weave_imp.o I tried the same example on my Windows XP, where neither python nor scipy paths ( which is not in Python directory) have spaces and it compiles without errors. As a relatively quick fix, I would move scipy on a path without spaces, just move directory and link to new parent directory in easy-install.path. A quick look at my compilation log, shows that only spaces in the scipy.weave path are relevant. The spaces in the python shouldn't be a problem, because your link and include directories, e.g. -L"C:\Program Files\pythonxy\python\libs" seem all to be correctly quoted for the Windows command shell. I usually avoid any paths with spaces, because getting the quoting always right is a pain with programs that don't put in the correct quotes, e.g. pythons subprocess.popen. Josef