*Ok, I've made all of the advised changes and it still didn't work. I've just tried pasting my helper command into command prompt and it just seems to hang. I tried the following:* ----- D:\Squid>d:/Squid/lib/squid/ext_ldap_group_acl.exe -d -S -b "ou=Domain_Groups,dc=domain-uk,dc=com" -f %g=Internet_Users -h srvham09.domain-uk.com D:\Squid>d:/Squid/lib/squid/ext_ldap_group_acl.exe -d -S -b "ou=Domain_Groups,dc=domain-uk,dc=com" -f Internet_Users -h srvham09.domain-uk.com D:\Squid>d:/Squid/lib/squid/ext_ldap_group_acl.exe -d -b "ou=Domain_Groups,dc=domain-uk,dc=com" -f %u "Internet_Users" -h srvham09.domain-uk.com D:\Squid>d:/Squid/lib/squid/ext_ldap_group_acl.exe -d -b ou=Domain_Groups,dc=domain-uk,dc=com -f %u %g=Internet_Users -h srvham09.domain-uk.com D:\Squid>d:/Squid/lib/squid/ext_ldap_group_acl.exe -v 2 -d -b ou=Domain_Groups,dc=domain-uk,dc=com -f Internet_Users -h srvham09.domain-uk.com ----- *I'm also seeing the following in the cache.log each time I try to access a webpage as a user who is a member of Internet_Users, is this anything to be concerned about?* ---- 2015/02/11 12:21:47 kid1| helperOpenServers: Starting 1/80 'ntlm_fake_auth' processes 2015/02/11 12:21:47 kid1| WARNING: no_suid: setuid(0): (22) Invalid argument ---- *And now, just to top things off I have errors in the cache.log stating:* d:/Squid/lib/squid/ext_ldap_group_acl.exe: (6) No such device or address *Quickly losing faith :-(* -- View this message in context: http://squid-web-proxy-cache.1019090.n4.nabble.com/Squid-3-5-1-NTLM-and-LDAP-tp4669661p4669727.html Sent from the Squid - Users mailing list archive at Nabble.com. _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users