I've successfully replicated this on both my laptop and my desktop. User Account control is turned off on both machines. Python exists in non C:\ partitions on both. I download the easy_install package, run setup python install in the directory, and get the following: Microsoft Windows [Version 6.0.6001] Copyright (c) 2006 Microsoft Corporation. All rights reserved. <root>\setuptools-0.6c9>python setup.py install running install running bdist_egg running egg_info writing setuptools.egg-info\PKG-INFO writing top-level names to setuptools.egg-info\top_level.txt writing dependency_links to setuptools.egg-info\dependency_links.txt writing entry points to setuptools.egg-info\entry_points.txt reading manifest file 'setuptools.egg-info\SOURCES.txt' writing manifest file 'setuptools.egg-info\SOURCES.txt' installing library code to build\bdist.win-amd64\egg running install_lib running build_py creating build creating build\lib copying pkg_resources.py -> build\lib copying easy_install.py -> build\lib copying site.py -> build\lib creating build\lib\setuptools copying setuptools\archive_util.py -> build\lib\setuptools copying setuptools\depends.py -> build\lib\setuptools copying setuptools\dist.py -> build\lib\setuptools copying setuptools\extension.py -> build\lib\setuptools copying setuptools\package_index.py -> build\lib\setuptools copying setuptools\sandbox.py -> build\lib\setuptools copying setuptools\__init__.py -> build\lib\setuptools creating build\lib\setuptools\command copying setuptools\command\alias.py -> build\lib\setuptools\command copying setuptools\command\bdist_egg.py -> build\lib\setuptools\command copying setuptools\command\bdist_rpm.py -> build\lib\setuptools\command copying setuptools\command\bdist_wininst.py -> build\lib\setuptools\command copying setuptools\command\build_ext.py -> build\lib\setuptools\command copying setuptools\command\build_py.py -> build\lib\setuptools\command copying setuptools\command\develop.py -> build\lib\setuptools\command copying setuptools\command\easy_install.py -> build\lib\setuptools\command copying setuptools\command\egg_info.py -> build\lib\setuptools\command copying setuptools\command\install.py -> build\lib\setuptools\command copying setuptools\command\install_egg_info.py -> build\lib\setuptools\command copying setuptools\command\install_lib.py -> build\lib\setuptools\command copying setuptools\command\install_scripts.py -> build\lib\setuptools\command copying setuptools\command\register.py -> build\lib\setuptools\command copying setuptools\command\rotate.py -> build\lib\setuptools\command copying setuptools\command\saveopts.py -> build\lib\setuptools\command copying setuptools\command\sdist.py -> build\lib\setuptools\command copying setuptools\command\setopt.py -> build\lib\setuptools\command copying setuptools\command\test.py -> build\lib\setuptools\command copying setuptools\command\upload.py -> build\lib\setuptools\command copying setuptools\command\__init__.py -> build\lib\setuptools\command creating build\lib\setuptools\tests copying setuptools\tests\doctest.py -> build\lib\setuptools\tests copying setuptools\tests\test_packageindex.py -> build\lib\setuptools\tests copying setuptools\tests\test_resources.py -> build\lib\setuptools\tests copying setuptools\tests\__init__.py -> build\lib\setuptools\tests copying setuptools\cli.exe -> build\lib\setuptools copying setuptools\gui.exe -> build\lib\setuptools creating build\bdist.win-amd64 creating build\bdist.win-amd64\egg copying build\lib\easy_install.py -> build\bdist.win-amd64\egg copying build\lib\pkg_resources.py -> build\bdist.win-amd64\egg creating build\bdist.win-amd64\egg\setuptools copying build\lib\setuptools\archive_util.py -> build\bdist.win-amd64\egg\setupt ools copying build\lib\setuptools\cli.exe -> build\bdist.win-amd64\egg\setuptools creating build\bdist.win-amd64\egg\setuptools\command copying build\lib\setuptools\command\alias.py -> build\bdist.win-amd64\egg\setup tools\command copying build\lib\setuptools\command\bdist_egg.py -> build\bdist.win-amd64\egg\s etuptools\command copying build\lib\setuptools\command\bdist_rpm.py -> build\bdist.win-amd64\egg\s etuptools\command copying build\lib\setuptools\command\bdist_wininst.py -> build\bdist.win-amd64\e gg\setuptools\command copying build\lib\setuptools\command\build_ext.py -> build\bdist.win-amd64\egg\s etuptools\command copying build\lib\setuptools\command\build_py.py -> build\bdist.win-amd64\egg\se tuptools\command copying build\lib\setuptools\command\develop.py -> build\bdist.win-amd64\egg\set uptools\command copying build\lib\setuptools\command\easy_install.py -> build\bdist.win-amd64\eg g\setuptools\command copying build\lib\setuptools\command\egg_info.py -> build\bdist.win-amd64\egg\se tuptools\command copying build\lib\setuptools\command\install.py -> build\bdist.win-amd64\egg\set uptools\command copying build\lib\setuptools\command\install_egg_info.py -> build\bdist.win-amd6 4\egg\setuptools\command copying build\lib\setuptools\command\install_lib.py -> build\bdist.win-amd64\egg \setuptools\command copying build\lib\setuptools\command\install_scripts.py -> build\bdist.win-amd64 \egg\setuptools\command copying build\lib\setuptools\command\register.py -> build\bdist.win-amd64\egg\se tuptools\command copying build\lib\setuptools\command\rotate.py -> build\bdist.win-amd64\egg\setu ptools\command copying build\lib\setuptools\command\saveopts.py -> build\bdist.win-amd64\egg\se tuptools\command copying build\lib\setuptools\command\sdist.py -> build\bdist.win-amd64\egg\setup tools\command copying build\lib\setuptools\command\setopt.py -> build\bdist.win-amd64\egg\setu ptools\command copying build\lib\setuptools\command\test.py -> build\bdist.win-amd64\egg\setupt ools\command copying build\lib\setuptools\command\upload.py -> build\bdist.win-amd64\egg\setu ptools\command copying build\lib\setuptools\command\__init__.py -> build\bdist.win-amd64\egg\se tuptools\command copying build\lib\setuptools\depends.py -> build\bdist.win-amd64\egg\setuptools copying build\lib\setuptools\dist.py -> build\bdist.win-amd64\egg\setuptools copying build\lib\setuptools\extension.py -> build\bdist.win-amd64\egg\setuptool s copying build\lib\setuptools\gui.exe -> build\bdist.win-amd64\egg\setuptools copying build\lib\setuptools\package_index.py -> build\bdist.win-amd64\egg\setup tools copying build\lib\setuptools\sandbox.py -> build\bdist.win-amd64\egg\setuptools creating build\bdist.win-amd64\egg\setuptools\tests copying build\lib\setuptools\tests\doctest.py -> build\bdist.win-amd64\egg\setup tools\tests copying build\lib\setuptools\tests\test_packageindex.py -> build\bdist.win-amd64 \egg\setuptools\tests copying build\lib\setuptools\tests\test_resources.py -> build\bdist.win-amd64\eg g\setuptools\tests copying build\lib\setuptools\tests\__init__.py -> build\bdist.win-amd64\egg\setu ptools\tests copying build\lib\setuptools\__init__.py -> build\bdist.win-amd64\egg\setuptools copying build\lib\site.py -> build\bdist.win-amd64\egg byte-compiling build\bdist.win-amd64\egg\easy_install.py to easy_install.pyc byte-compiling build\bdist.win-amd64\egg\pkg_resources.py to pkg_resources.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\archive_util.py to archive_u til.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\alias.py to alias.py c byte-compiling build\bdist.win-amd64\egg\setuptools\command\bdist_egg.py to bdis t_egg.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\bdist_rpm.py to bdis t_rpm.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\bdist_wininst.py to bdist_wininst.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\build_ext.py to buil d_ext.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\build_py.py to build _py.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\develop.py to develo p.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\easy_install.py to e asy_install.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\egg_info.py to egg_i nfo.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\install.py to instal l.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\install_egg_info.py to install_egg_info.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\install_lib.py to in stall_lib.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\install_scripts.py t o install_scripts.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\register.py to regis ter.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\rotate.py to rotate. pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\saveopts.py to saveo pts.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\sdist.py to sdist.py c byte-compiling build\bdist.win-amd64\egg\setuptools\command\setopt.py to setopt. pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\test.py to test.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\upload.py to upload. pyc byte-compiling build\bdist.win-amd64\egg\setuptools\command\__init__.py to __ini t__.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\depends.py to depends.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\dist.py to dist.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\extension.py to extension.py c byte-compiling build\bdist.win-amd64\egg\setuptools\package_index.py to package_ index.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\sandbox.py to sandbox.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\tests\doctest.py to doctest. pyc byte-compiling build\bdist.win-amd64\egg\setuptools\tests\test_packageindex.py t o test_packageindex.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\tests\test_resources.py to t est_resources.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\tests\__init__.py to __init_ _.pyc byte-compiling build\bdist.win-amd64\egg\setuptools\__init__.py to __init__.pyc byte-compiling build\bdist.win-amd64\egg\site.py to site.pyc creating build\bdist.win-amd64\egg\EGG-INFO copying setuptools.egg-info\PKG-INFO -> build\bdist.win-amd64\egg\EGG-INFO copying setuptools.egg-info\SOURCES.txt -> build\bdist.win-amd64\egg\EGG-INFO copying setuptools.egg-info\dependency_links.txt -> build\bdist.win-amd64\egg\EG G-INFO copying setuptools.egg-info\entry_points.txt -> build\bdist.win-amd64\egg\EGG-IN FO copying setuptools.egg-info\top_level.txt -> build\bdist.win-amd64\egg\EGG-INFO copying setuptools.egg-info\zip-safe -> build\bdist.win-amd64\egg\EGG-INFO creating dist creating 'dist\setuptools-0.6c9-py2.6.egg' and adding 'build\bdist.win-amd64\egg ' to it removing 'build\bdist.win-amd64\egg' (and everything under it) Processing setuptools-0.6c9-py2.6.egg Removing g:\python26\lib\site-packages\setuptools-0.6c9-py2.6.egg Copying setuptools-0.6c9-py2.6.egg to g:\python26\lib\site-packages setuptools 0.6c9 is already the active version in easy-install.pth Installing easy_install-script.py script to G:\Python26\Scripts Installing easy_install.exe script to G:\Python26\Scripts Installing easy_install-2.6-script.py script to G:\Python26\Scripts Installing easy_install-2.6.exe script to G:\Python26\Scripts Installed g:\python26\lib\site-packages\setuptools-0.6c9-py2.6.egg Processing dependencies for setuptools==0.6c9 Finished processing dependencies for setuptools==0.6c9 <root>\setuptools-0.6c9>easy_install numpy *Cannot find Python executable G:\Python26\python.exe* <root>\setuptools-0.6c9>cd G:\Python26\Scripts G:\Python26\Scripts>easy_install-2.6.exe Cannot find Python executable G:\Python26\python.exe G:\Python26\Scripts> The easy_install app does not work. I can use the easy_install-2.6-script.py, however. The weird thing is that the error message makes absolutely no sense to me. As part of the install process I obviously had to run python, and the installer put files (correctly) into the site-packages directory and all of the other dirs. Ideas?