You probably don't authenticate, either. WMP has had "issues" (yeh - we'll go with that) with authenticating proxies and specific WPAD server names for quite some time. http://blogs.isaserver.org/shinder/2007/11/22/fixing-windows-media-player-authentication-prompts/ From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of Steve Moffat Sent: Tuesday, August 11, 2009 11:16 AM To: ISA Mailing List Subject: [isalist] Re: Windows 7 Eh?? It's always worked for me. From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of Ball, Dan Sent: Tuesday, August 11, 2009 1:57 PM To: ISA Mailing List Subject: [isalist] Windows 7 I see they finally fixed the media player issues with Windows 7, streaming video from CNN works again through ISA 2006!