Installing SetupTools on 64-bit Windows


I"m running Python 2.7 on Windows 7 64-bit, and when I run the installer for setuptools it tells me that Python 2.7 is not installed. The specific error message is:

`Python Version 2.7 required which was not found in the registry`

My installed version of Python is:

`Python 2.7 (r27:82525, Jul  4 2010, 07:43:08) [MSC v.1500 64 bit (AMD64)] on win32`

I"m looking at the setuptools site and it doesn"t mention any installers for 64-bit Windows. Have I missed something or do I have to install this from source?

Answer rating: 142

Problem: you have 64-bit Python, and a 32-bit installer. This will cause problems for extension modules.

The reasons why the installer doesn"t finds Python is the transparent 32-bit emulation from Windows 7. 64-bit and 32-bit programs will write to different parts of the Windows registry.


32-bit: HKLM|HKCUSOFTWAREwow6432node.

This means that the 64-bit Python installer writes to HKLMSOFTWAREPython, but the 32-bit setuptools installer looks at HKLMSOFTWAREwow6432nodePython (this is handled by windows automatically, programs don"t notice). This is expected behavior and not a bug.

Usually, you have these choices:

  • the "clean" way: use 32-bit Python if you have to use 32-bit modules or extensions
  • the other "clean" way: only use 64-bit installers when using 64-bit Python (see below)
  • what the answer above suggests: copy HKLMSOFTWAREPython to HKLMSOFTWAREwow6432nodePython, but this will cause problems with binary distributions, as 64-bit Python can"t load 32-bit compiled modules (do NOT do this!)
  • install pure Python modules with setuptools instead of the distutils installer (easy_install or pip)

For setuptools itself, for example, you can"t use a 32-bit installer for 64-bit Python as it includes binary files. But there"s a 64-bit installer at (has many installers for other modules too). Nowadays, many packages on PyPi have binary distributions, so you can install them via pip.

Get Solution for free from DataCamp guru