Originally I tried 3.2.2 (32bit), but I've just checked 3.2.3 and got the same.
A code for reproduce is simple:

from socket import gethostbyaddr
a = gethostbyaddr('127.0.0.1')

leads to:
Traceback (most recent call last):
  File "C:\Users\user\test\test.py", line 13, in <module>
    a = gethostbyaddr('127.0.0.1')
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xcf in position 5: invalid continuation byte

Or more complex sample:

def main():
    import http.server
    port = 80
    handlerClass = http.server.SimpleHTTPRequestHandler
    srv = http.server.HTTPServer(("", port), handlerClass )
    srv.serve_forever()
if __name__ == "__main__":
    main()

Attempt of connection to the server leads to:

----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 1156)
Traceback (most recent call last):
  File "C:\Python32\lib\socketserver.py", line 284, in _handle_request_noblock
    self.process_request(request, client_address)
  File "C:\Python32\lib\socketserver.py", line 310, in process_request
    self.finish_request(request, client_address)
  File "C:\Python32\lib\socketserver.py", line 323, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "C:\Python32\lib\socketserver.py", line 637, in __init__
    self.handle()
  File "C:\Python32\lib\http\server.py", line 396, in handle
    self.handle_one_request()
  File "C:\Python32\lib\http\server.py", line 384, in handle_one_request
    method()
  File "C:\Python32\lib\http\server.py", line 657, in do_GET
    f = self.send_head()
  File "C:\Python32\lib\http\server.py", line 701, in send_head
    self.send_response(200)
  File "C:\Python32\lib\http\server.py", line 438, in send_response
    self.log_request(code)
  File "C:\Python32\lib\http\server.py", line 483, in log_request
    self.requestline, str(code), str(size))
  File "C:\Python32\lib\http\server.py", line 517, in log_message
    (self.address_string(),
  File "C:\Python32\lib\http\server.py", line 559, in address_string
    return socket.getfqdn(host)
  File "C:\Python32\lib\socket.py", line 355, in getfqdn
    hostname, aliases, ipaddrs = gethostbyaddr(name)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xcf in position 5: invalid continuation byte
----------------------------------------

P.S. My PC name is "USER-ПК"