SAMBA:
Add machine to the linux pdc:
Login as root:
# useradd -s /bin/false -d /dev/null stephen\$
PLEASE NOTE that a machine account has the "\$" at the end.
You should get something back from the system like this:
useradd: warning: the home directory already exists.
Not copying any file from skel directory into it.

Now set or change the unix password for samba.
# smbpasswd -a -m stephen
Added user stephen$.
restart smb
#service smb restart

Adding a user to samba:
# useradd stephen
# passwd stephen
Changing password for user stephen.
New UNIX password:
Retype new UNIX password:
passwd: all authentication tokens updated successfully.

Now change or set the password for the user in Samba
# smbpasswd -a stephen
New SMB password:
Retype new SMB password:
Added user stephen.

restart samba

NOTES FOR:
Win Vista:
1. Log onto the Vista computer with an Administrator account
2. Got to .Start. > .Run., type .secpol.msc.
3. Expand .Local Policies.
4. "Network Security: LAN Manager authentication level" and open it
5. By default Windows Vista sets the policy to "NTVLM2 responses only".
6. Change the authentication level to "LM and NTLM . use NTLMV2 session security if negotiated".
7. The computer should now be able to log onto the Samba server.

NOTE:
Add a Admin User (I think this is done on the win box) (and I think we need to add this user to unix and samba too.)
Go to control pannel, user accounts and click add. Enter the user name like
"Admin" under the domain of the Samba server.
Next, click on others to make him a member of local admin group,
Thats it