When trying to run Microsoft Update (http://update.microsoft.com/microsoftupdate/v6/default.aspx?ln=en-us) from behind an Apache Forward Proxy, the user will encouter error 0x80072EE2. This happens on WinXP, Win2K (Server and Workstation), and Win2K3 Server.
not really a surprise, it's a notoriously non-compliant app. But give it another try and report back, might be fixed now by ms.
just guessing, re-open if this still occurs on recent level of Apache *** This bug has been marked as a duplicate of bug 18757 ***