Squid Auth question for machines not belonging to a AD domain

["Markus Moeller" <huaraz@xxxxxxxxxxxxxxxx>]

Does anybody know how a Windows client determines the right authentication 
mechanism ?  I have a case where most clients are on a Windows domain and 
squid_kerb_auth works fine. Now I have clients from visitors which have 
never been on the domain. Can I send to these clients a list of 
authentication mechanisms (e.g. Negotiate Digest Basic) ?  If so would the 
client choose always Negotiate with NTLM ?

Thank you
Markus