Next up is WinPython (http://winpython.github.io/, also suggested by freakzoid). WinPython is a modular Python distribution; for a list of packages included see sf.net/p/winpython/wiki/PackageIndex_27/ and sf.net/p/winpython/wiki/PackageIndex_33/.
WinPython is a free open-source portable distribution of the Python programming language for Windows Vista/7/8 and scientific and educational usage. It is a full-featured Python-based scientific environment. [...] WinPython is a portable application, so the user should not expect any integration into Windows explorer during installation. However, the WinPython Control Panel allows to "register" your distribution to Windows.
WinPython latest releases are v188.8.131.52, v184.108.40.206, and v220.127.116.11 (FYI, multiple versions correspond to the underlying Python core version) and can be downloaded in discreet 32 or 64 bit packages from http://winpython.github.io/.
Note that WinPython doesn't officially support Windows XP anymore, but there's a workaround in the documentation -- see github.com /winpython/winpython/wiki/Installation#windows-xp.
Sofpedia's review of WinPython can be found at www.softpedia.com /get/Programming/Coding-languages-Compilers/WinPython.shtml.