Workstation joining a domain

You may want to change the name of the computer to make sure it not already being used or has been used in the past. Also try using a different admin account to join the pc to the domain.

This error is almost always caused by already having an existing connection to the server while trying to join the domain. To check on this, bring up a command prompt on your Windows box and type net use. If it lists any connections to the server,do net use \\servername /delete and try joining the domain again.

We have had this problem in the past. The problem seems to be that even though the computer name has been deleted, Windows does not release it entirely. After a few days the problem resolves it self. Add it to the domain as a different computer for now and try to readd it to the domain with the desired computer name next week. Hope this helps.

Chances are that you are logged in with one account that does not have domain administrative capabilites, but when you are trying to join the computer to the domain, you are supplying another account (w/ privs), and this is where you are getting theerror. Two things I would suggest: log onto the PC w/ the domain admin account, then you will not be prompted for the admin username/password. OR you may want to check the admin account you are using. For security purposes, MS intentionally allows only certian admin accounts 10 computer joins to the domain. I believe this happens in the event of a normal domain account getting elevated to a domain admin. Check Microsoft Knowledge Base article # Q251335 for more info on this.

Error Message:
The credentials supplied conflict with an existing set of credentials.

Explanation:
Credentials are a username/password combination. In this case, you already have a logon session started with a set of credentials and have triedto start another session between the same computers, using the same set of credentials.

User Action:
Either end the existing session, or log on with a different set of credentials. Note that this message may not be caused by anything you did at the user interface, but can be caused by a running application (applications can log on as users). In that case, contact the supplier of the running application.

You may want to verify the SID (Security ID) on the computer. You absolutely need a unique SID in order to join a domain and if you used any type of Cloning software (such as ghost) to clone this PC you may have identical SID's with another PC on the network and therefore can't be joined to the domain. The fix is to :
1- verify the SID on problem PC and crossreference with the other PC's (may take long time)
2- use a SID changer utility to change the PC's SID (Symantec Ghostwalker or Newsid)

Should this be the case you can get this freeware and a more detailed explanation at
http://www.sysinternals.com/ntw2k/source/newsid.shtml#top

Login as your local Administrator computer, don't use others.

Then try register your computer through the network icon in the control panel. You should have the account of Domain Administrator Password to do this not others !.

If you have donethis before and still problem, try to reinstall you network service & protocol (unsintall first), network adapter also. Don't forget to reinstall your service pack 6 or later.

Hope it can help.