The `enum_types` function in `MimeTypes.read_windows_registry` tries to `.encode` the results of `EnumKey`, assuming it to be a Unicode string.

However, `_winreg.EnumKey` in Python 2.x actually returns a byte string (straight from the ANSI version of the registry interface). Consequently, if there is a MIME type registered with a non-ASCII character in its name (invalid, but not unheard of), initialising `MimeTypes` will raise a `UnicodeDecodeError`. This is not caught (it is only expecting a `UnicodeEncodeError`), so it bombs out whatever module indirectly caused `mimetypes.init()` to be called.

This attempt to `.encode` the `ctype` should simply be removed.