I am trying to understand the difficulty that you are having.
It sounds as if you are trying to add a Windows 2000 machine to a Samba PDC. I may need to get the full history of the Samba configuration but let me try something.
The credentials supplied conflict with an existing set of credentials.
This message normally occurs when you have a mapping to the existing server name and you are trying to add a machine to the domain. Make sure that nothing is mapped (e.g. drives) on the Windows 2000 machine.
In the # PDC's section of your smb.conf file change the line to
security = user
Security = domain suggests that a domain controller other than the PDC is going to authenticate users.
You may want to comment out these two lines.
update encrypted = yes
password level = 4
I have never seen them before and don't know what they do.
Here are the standard documents for creating a Samba PDC. Use the IBM tutorial first.
Remember to include the
domain logons = yes
command in your smb.conf file. This is required for Windows 2000/XP logons even though the literature suggests otherwise.
I strongly recommend that you use vi or some other text editor to create your smb.conf file. Swat and Webmin add all kinds of unnecessary stuff to the file.