Hi all, I have a Windows 2008 SP2 Active Directory Domain, which has clients of Vista, Win 2000 XP and Windows 7 as members. I installed Squid 2.7 Stable 8 on Windows 2008 SP2 trying to configure NTLM based authentication when surfing Internet. Basically have defined 2 groups for internet allow and deny based on authorization Internet access is allowed. But after trying for over 3 weeks, seems that the authentication does not happen. The browser keeps on asking for user name & password. I would like to know if there is any solution for this. I’m totally frustrated and unable to move forward. My configuration as below from the modifying the default squid.conf Line 292 auth_param ntlm program c:/squid/libexec/mswin_ntlm_auth.exe auth_param ntlm children 5 Line 626 acl localnet proxy_auth REQUIRED src 10.0.0.1/255 acl InetAllow external win_domain_group InternetUsers acl InetDeny external win_domain_group InternetDenyGroup http_access allow InetAllow http_access deny InetDeny Comment any "acl localnet src" Line 294 external_acl_type win_domain_group ttl=120 %LOGIN c:/squid/libexec/mswin_check_lm_group.exe –G My Windows 2008 server is running on 192.168.0.203 and clients are of subnet 10.0.0.x for which I need authentication. Pls help !!!