Check your smb.conf file for the line "security = ...".
If it's "security = share" then Samba is running like a Windows workstation without an NT domain - no user/password checking - and each share needs a separate password.
If it's "security = user" (most common) then Samba should handle the user/password authentication when you log in to a Windows client and check the credentials when you access a Samba share. You'll need to set up smb users and passwords with smbpasswd.
There are other possibilities but they more complicated.
I have my FC3 Linux box working like a Windows NT4 server and it runs fine with Windos 98 clients. The relevant entries from my smb.conf:
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[global]
# SMB Operation
netbios name =
your machine name
workgroup =
your NT domain name or workgroup
server string = Samba Server
os level = 64
wins support = Yes
time server = Yes
preferred master = Yes
domain master = Yes
local master = yes
dns proxy = No
# Unix Interface
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
# To avoid running Samba on a WAN interface like ppp0
; bind interfaces only = yes
; interfaces = eth0
hosts allow =
your local network/netmask
log file = /var/log/samba/%m.log
max log size = 0
strict locking = No
preserve case = yes
short preserve case = yes
case sensitive = no
# Security/User Management
security = user
encrypt passwords = yes
domain logons = Yes
admin users = root
username map = /etc/samba/smbusers
add user script = /usr/sbin/useradd -m '%u'
delete user script = /usr/sbin/userdel -r '%u'
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'
add machine script = /usr/sbin/useradd -s /bin/false -d /dev/null '%u'
ldap ssl = no
# Client Boot
logon path = \\%L\%U\profile
logon drive = X:
logon home = \\%L\%U\.profile
# Printing
cups options = raw
[IPC$]
path = /tmp
hosts allow =
your local network/netmask, 127.0.0.1
hosts deny = 0.0.0.0/0
[homes]
comment = Home Directories
valid users = %S
read only = No
browseable = No
[netlogon]
comment = Network Logon Scripts
path = /usr/share/netlogon
write list =
list of admins
[tmp]
comment = Temporary file space
path = /tmp
read only = No
guest ok = Yes
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The Troubleshooting section of the
Samba HowTo has a useful checklist for tracking down problems.