I must be missing something obvious in installing Python 3.4.2...

[Andrew Koenig]

Fixed it!

The aforementioned article is correct. I downloaded the RegDelNull program mentioned in the article (http://technet.microsoft.com/en-us/sysinternals/bb897448.aspx) and ran it on hkcr, hkcu, hklm, hku, and hkcc (short for HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS, and HKEY_CURRENT_CONFIG), respectively. It deleted a bunch of keys. Rerunning the program you posted earlier revealed no keys with embedded nulls in their names, and ensurepip now works.

I have no idea how these keys got there. For all I know they are the result of malware.

I think it would be worthwhile changing the Python code to detect nulls and perhaps issue a warning that directs people to this article or something like it.