Hello, I would also love to use this on Windows XP (my company uses XP Embedded, whose end of life is still a few years in the future afaik). I got past the inet_pton() function by doing it myself with WSAStringToAddress() but GetQueuedCompletionStatusEx() is harder. Still, nice work! Tried to create a simple chat app and everything just works. :-) -- Oskari Timperi oskari.timperi@xxxxxx