Starting at Python 3.2, the MBCS codec uses MultiByteToWideChar() to decode bytes using flags=MB_ERR_INVALID_CHARS by default (strict error handler), flags=0 for the ignore error handler, and raise a ValueError for other error handlers.

The problem is that the meaning of flags=0 changes with the Windows version:

 - ignore undecodable bytes until Windows XP
 - *replace* undecodable bytes for Windows Vista and later

We should accept "replace" error handler with flags=0, at least on Windows Vista and later.

I don't know if we should only accept "ignore" on Windows <= XP and only "error" on Windows >= Vista, or if the difference should be documented.