This in from python-list.  2 complaints.  
conflict with a notepad++ plugin and incorrect permissions.

Date:    Fri, 11 Dec 2015 16:30:32 +0000
To:      "python-list@python.org" <python-list@python.org>
From:    Jay Hamm <hammj@vmware.com>
Subject: python 351x64


Hi

I was trying to use your windows version of python 3.5.1 x64.

It has a conflict with a notepad++ plugin NppFTP giving api-ms-win-crt-runtime-
I1-1-0.dll error on start up.

This seems pretty well documented on the web. The work around is to delete the 
plugin and reinstall since it borks the install.

Since about every other admin I've ever known uses notepad++, you might want to
 fix this.

Also your installer fails to set the permissions correctly:

H:\>py -m pip install requests
Collecting requests
  Downloading requests-2.8.1-py2.py3-none-any.whl (497kB)
    100% |################################| 499kB 875kB/s
Installing collected packages: requests
Exception:
Traceback (most recent call last):
  File "C:\Program Files\Python35\lib\site-packages\pip\basecommand.py", line 2
11, in main    status = self.run(options, args)
  File "C:\Program Files\Python35\lib\site-packages\pip\commands\install.py", l
ine 311, in run    root=options.root_path,
  File "C:\Program Files\Python35\lib\site-packages\pip\req\req_set.py", line 6
46, in install    **kwargs
  File "C:\Program Files\Python35\lib\site-packages\pip\req\req_install.py", li
ne 803, in install    self.move_wheel_files(self.source_dir, root=root)
  File "C:\Program Files\Python35\lib\site-packages\pip\req\req_install.py", li
ne 998, in move_wheel_files    isolated=self.isolated,
  File "C:\Program Files\Python35\lib\site-packages\pip\wheel.py", line 339, in
 move_wheel_files    clobber(source, lib_dir, True)
  File "C:\Program Files\Python35\lib\site-packages\pip\wheel.py", line 310, in
 clobber    ensure_dir(destdir)
  File "C:\Program Files\Python35\lib\site-packages\pip\utils\__init__.py", lin
e 71, in ensure_dir    os.makedirs(path)
  File "C:\Program Files\Python35\lib\os.py", line 241, in makedirs    mkdir(na
me, mode) PermissionError: [WinError 5] Access is denied: 'C:\\Program Files\\P
ython35\\Lib\\site-packages\\requests'

Once I gave myself control it started working.

This is pretty shoddy for released software.
Thanks,
Jacob Hamm (Jay) VCP-DCV, RHCE
Senior Cloud Services Engineer - VMware vCloud Air

380 Interlocken Crescent Blvd - Ste 500, Broomfield CO 80021
Office 303 942 4638 - hammj@vmware.com<mailto:hammj@vmware.com>
Want to learn more about VMware vCloud Air?
Go to http://vcloud.vmware.com/tutorials
[vCloudAir]

Responded on python-list.

For the record Zach's conclusion is that the conflict is a NppFTP issue, since api-ms-win-crt-runtime is part of the CRT and so any problem would not be unique to Python (or solvable by python).  The permissions issue is more obvious: that's how it is designed to work, and this is a documented change between python3.4 and python3.5, bringing it more in-line with how other Windows software works permissions-wise.

And for future reference, anyone who has Python in Program Files has *explicitly* chosen to put it there. We always default to a location where the current user can install packages as normal.

Right, I should have been more specific here.  Sorry about that.