I can't install pygraphviz on Windows XP. I'm using Python27. Before to launch the setup I've changet these two variables of the setup.py file library_path="C:\\Archivos de programa\\Graphviz 2.28\\bin" include_path="C:\\Archivos de programa\\Graphviz 2.28\\include\\graphviz" Then I've launched the setup. I'm using mingw32 as a compiler. I don't know what can I do now. I'm using the following command: C:\Python27\pygraphviz-1.1>c:\python27\python setup.py build -c mingw32 And I've got the folling result library_path=C:\Archivos de programa\Graphviz 2.28\bin include_path=C:\Archivos de programa\Graphviz 2.28\include\graphviz running build running build_py running build_ext building 'pygraphviz._graphviz' extension C:\MinGW\bin\gcc.exe -mno-cygwin -mdll -O -Wall "-IC:\Archivos de programa\Graphviz 2.28\include\graphviz" -Ic:\python27\include -Ic:\python 27\PC -c pygraphviz/graphviz_wrap.c -o build\temp.win32-2.7\Release\pygraphviz\graphviz_wrap.o pygraphviz/graphviz_wrap.c: In function 'agattr_label': pygraphviz/graphviz_wrap.c:2855:5: warning: return makes integer from pointer without a cast writing build\temp.win32-2.7\Release\pygraphviz\_graphviz.def Traceback (most recent call last): File "setup.py", line 146, in <module> package_data = package_data File "c:\python27\lib\distutils\core.py", line 152, in setup dist.run_commands() File "c:\python27\lib\distutils\dist.py", line 953, in run_commands self.run_command(cmd) File "c:\python27\lib\distutils\dist.py", line 972, in run_command cmd_obj.run() File "c:\python27\lib\distutils\command\build.py", line 127, in run self.run_command(cmd_name) File "c:\python27\lib\distutils\cmd.py", line 326, in run_command self.distribution.run_command(command) File "c:\python27\lib\distutils\dist.py", line 972, in run_command cmd_obj.run() File "c:\python27\lib\distutils\command\build_ext.py", line 340, in run self.build_extensions() File "c:\python27\lib\distutils\command\build_ext.py", line 449, in build_extensions self.build_extension(ext) File "c:\python27\lib\distutils\command\build_ext.py", line 531, in build_extension target_lang=language) File "c:\python27\lib\distutils\ccompiler.py", line 741, in link_shared_object extra_preargs, extra_postargs, build_temp, target_lang) File "c:\python27\lib\distutils\cygwinccompiler.py", line 260, in link target_lang) File "c:\python27\lib\distutils\unixccompiler.py", line 218, in link libraries) File "c:\python27\lib\distutils\ccompiler.py", line 1121, in gen_lib_options opt = compiler.runtime_library_dir_option(dir) File "c:\python27\lib\distutils\unixccompiler.py", line 285, in runtime_library_dir_option compiler = os.path.basename(sysconfig.get_config_var("CC")) File "c:\python27\lib\ntpath.py", line 198, in basename return split(p)[1] File "c:\python27\lib\ntpath.py", line 170, in split d, p = splitdrive(p) File "c:\python27\lib\ntpath.py", line 125, in splitdrive if p[1:2] == ':': TypeError: 'NoneType' object is not subscriptable Any idea on how to solve it over windows? In other computer with Ubuntu I've installed without problems.