[Samba] question : PDC setup

[bino at indoakses-online.com]

Dear All ...

I set a samba and webmin server.

Currently when I set my XP pro station as "work group" member
(workgroupname is "INAXSMB"), it can login to samba with proper username
and password (defined via webmin)

But when I change the network type from "workgroup" to "domain" it say
"the user name could not be found".

Here is my smb.conf
#####START#############
[global]
    passwd chat debug = yes
    name resolve order = wins bcast hosts
    passwd chat = *Enter\snew\sUNIX\spassword:* %n\n
*Retype\snew\sUNIX\spassword:* %n\n .
    idmap gid = 15000-20000
    add group script = /usr/sbin/groupadd %g
    delete group script = /usr/sbin/groupdel %g
    add user to group script = /usr/sbin/usermod -G %g %u
    username map = /etc/samba/smbusers
    passwd program = /usr/bin/passwd %u
    passdb backend = tdbsam
    wins support = true
    netbios name = erp_int
    writeable = yes
    server string = %h server (Samba, Ubuntu)
    idmap uid = 15000-20000
    default = global
    unix password sync = yes
    remote announce = 192.168.0.0
    workgroup = inaxsmb
    os level = 64
    add user script = /usr/sbin/useradd -m %u
    security = user
    add machine script = /usr/sbin/useradd -s /bin/false/ -d
/var/lib/nobody %u
    delete user script = /usr/sbin/userdel -r %u
    log level = 3
    domain master = yes
    domain logons = yes
# Useradd scripts
# sync smb passwords woth linux passwords
# set the loglevel
[homes]
comment = Home
valid users = %S
read only = no
browsable = no
[netlogon]
comment = Network Logon Service
path = /home/samba/netlogon
admin users = Administrator
valid users = %U
read only = no
[profile]
comment = User profiles
path = /home/samba/profiles
valid users = %U
create mode = 0600
directory mode = 0700
writable = yes
browsable = no


[bag_umum]
    comment = Bag.Umum
    path = /home/samba/bagumum
#####END#############

Basically, I want every user has to be authenticated before it can joint
the samba shares.
Is it doable just with "workgroup" ? or is it need "PDC" ?

If it need PDC , how to set samba as PDC ? and how to set windows client
to able to joint that PDC ?

Kindly please give me any of your enlightment.

Sincerely
-bino-