I'd be happy to submit a PR to resolve all the issues that I note here. Just say the word and I'll go right ahead.

I presume the Windows installer code [0a] should be updated to refuse to install on Windows <8 and given an informative warning instead letting the user know their system is not supported, as well as logging the appropriate messages in each case? Appropriate failure IDs would also be defined in the associated WXL [0b].

[0a] https://github.com/python/cpython/blob/master/Tools/msi/bundle/bootstrap/PythonBootstrapperApplication.cpp#L3041
[0b] https://github.com/python/cpython/blob/master/Tools/msi/bundle/Default.wxl

The relevant Using Python on Windows docs [1a] should be updated to reflect this, along with PCBuild/readme.txt [1b]. Also, given it is dropping 2 major Windows versions, including one seeing widespread use, it should probably be mentioned in What's New; I don't see it there as it stands now.

[1a] https://github.com/python/cpython/blob/master/Doc/using/windows.rst
[1b] https://github.com/python/cpython/blob/master/PCbuild/readme.txt

As a more trivial docs change, references to "Vista's" UAC ([2a], [2b], [2c]) could be updated to simply refer to "Windows'" UAC to avoid confusion since it presumably applies to all >=Vista versions which have said feature.

[2a] https://github.com/python/cpython/blob/master/Lib/distutils/command/bdist_wininst.py#L52
[2b] https://github.com/python/cpython/blob/master/PC/bdist_wininst/install.c#L2187
[2c] https://github.com/python/cpython/blob/master/Doc/distutils/builtdist.rst#vista-user-access-control-uac

Finally, maybe this is stretching the scope a bit, but the relevant part of [1a], namely [3a], should also be updated to state that Windows CE is not supported (it currently states the opposite), as this was removed in 3.6.0b1 [3ai], and additionally the Sourceforge (!) project it links to [3bii] is on an legacy archived CVS repo that hasn't been meaningfully updated since 2008 and the current versions of CE (5 and 6) at the time is long EoL now (in fact, 7 is coming up on its EoL in a year). Out of date references to Windows CE support could also be removed from the ctypes doc [3b] and the condavar code comments [3c], [3d].

[3a] https://github.com/python/cpython/blob/master/Doc/using/windows.rst#L1165
    [3ai] https://github.com/python/cpython/blob/master/Misc/NEWS.d/3.6.0b1.rst#L217
    [3aii] https://sourceforge.net/projects/pythonce/files/
[3b] https://github.com/python/cpython/blob/master/Doc/library/ctypes.rst 
[3c] https://github.com/python/cpython/blob/master/Include/internal/pycore_condvar.h#L30
[3d] https://github.com/python/cpython/blob/master/Python/condvar.h#L85