Windows updates using WPAD

Hi!

I've read many post related to issues with WPAD and winhhtp but I can't find any clear answer about what goes wron and how to solve it....

So I'll try to be as factual as possible, hopping someone could answer this mystery.

First : Does Windows Update use winhhtp (in Windows 7 pro ) ?

          -> Microsoft say YES : http://support.microsoft.com/kb/900935/en

          -> In windows update logs I can found : WARNING: WinHttp: SendRequestUsingProxy failed for <http://download.windowsupdate.com/v9/1/windowsupdate/redir/muv4wuredir.cab>. error 0x8024402c

        ==> Conclusion : winhttp handle http request for winupdate.

Second : How does winhttp get proxy parameters ?

        -> Quote from microsoft : "The Automatic Updates service does not have access to the user-specific proxy server settings that may be configured in Internet Explorer" and "If theAutomatically detect settings check box is selected in Internet Explorer, the Windows Update client uses the WPAD feature to locate a proxy server" (source : http://support.microsoft.com/kb/900935/en) ... Ok I'm a bit confused now : winUpdate does not care about IE proxy setting BUT if IE use WPAD, winUpdate do the same ?er

       -> Let's do some test :

            IE set with manual proxy 123.123.123.123:123 =>netsh winhttp show proxy returns 123.123.123.123:123 (so winhhtp care about IE settings ?)

            IE set with pacfile = wpad.mycorp.org/wpad.dat =>netsh winhttp show proxy returns NO PROXY

            IE set proxy to auto :  =>netsh winhttp show proxy returns NO PROXY (does it really use no proxy are does it ause wpad as described by microsoft ?)

Finally :

I've tried to start some service like WinHttpAutoProxySvc without any effect.

Does anyone know why winhttp refuse to use WPAD and how to solve it. (I've read some "solution" : usingnetsh winhttp set proxy proxyservername:portnumber But I really would like use WPAD and not statically configure winhttp ....

Additional info : WPAD works well for all pllication (IE included)

                         WPAD is published via DNS (2003 server)  and DHCP ( cisco IOS)

I can post any other usefull information if asked.

Thanks for reading.

PS: sorry for poor written english