Hi, My test lab environment consists of a Squid 2.7.STABLE4 for i686-pc-winnt (windows 2003R2 SP1) proxy server and Windows XP (SP3) IE8 client (IWA enabled), if I specify the proxy server IP address in IE8 client and use mswin_ntlm_auth.exe auth helper, NTLMv1 or NTLMv2 authentication happens transparently (verified using wireshark), specifically I do not get authentication popup window. However, if I specify the proxy IP address in IE client and use mswin_negotiate_auth.exe I get authentication popup window and have to manually enter a username and password; is this a bug or know issue in mswin_negotiate_auth.exe? Thank you, Best Regards - Colin Unless otherwise stated, this email has been sent from Fujitsu Services Limited, from Fujitsu (FTS) Limited, or from Fujitsu Telecommunications Europe Limited, together "Fujitsu". This email is only for the use of its intended recipient. Its contents are subject to a duty of confidence and may be privileged. Fujitsu does not guarantee that this email has not been intercepted and amended or that it is virus-free. Fujitsu Services Limited, registered in England No 96056, registered office 22 Baker Street, London W1U 3BW. Fujitsu (FTS) Limited, registered in England No 03808613, registered office 22 Baker Street, London W1U 3BW. Fujitsu Telecommunications Europe Limited, registered in England No 2548187, registered office Solihull Parkway, Birmingham Business Park, Birmingham, B37 7YU.