HI I've managed to get wpad.dat to work on most of our PCs, using "automatic detect settings" on internet explorer (with versions from 6 to 7). Now I have 2 problems: 1 - some pc's always ask for credentials when using the auto proxy configuration. If I choose the proxy manually, everything goes fine. 2 - Some other options, like the on-line help of some applications also ask for credentials. The top of the squid file looks like this: auth_param ntlm program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp auth_param ntlm children 30 auth_param ntlm max_challenge_reuses 0 auth_param ntlm max_challenge_lifetime 2 minutes auth_param ntlm use_ntlm_negotiate off auth_param basic program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-basic auth_param basic children 5 auth_param basic realm Squid proxy-caching web server auth_param basic crendentialsttl 5 hours ext_acl_type group_nt %LOGIN /usr/lib/squid/wbinfo_group.pl winbind seems to be working fine. Can someone please point me the right direction? Thanks!