http://bugs.winehq.org/show_bug.cgi?id=15107
--- Comment #11 from Hans Leidekker hans@meelstraat.net 2008-09-03 11:06:17 --- You could check if WINHTTP_FLAG_ASYNC is set in request->hdr.flags but I fear that that won't get you much further. Perhaps you could try native winhttp and find out what else is missing from Wine?