In attempting to join a computer with Windows XP Professional to a network, I received the following error message - The user name you typed is the same as the user name you logged in with. That user name has already been tried. A domain controller cannot be found to verify that user name.

The server is Windows 2000. It works for some time but then acts like a workgroup asking for a user name and password to access other computers in the network.

If this is a server based network. Each computer name on the network has to be unique. In addition, any user name used to logon has to be an established account on the server.

Have you talked to the LAN Admin about this?

To join a computer to a domain, you must use a domain user account. You must logon to the computer with local administrator rights.

Also, unless the domain account being used to join the computer to the domain is a domain administrator account, then there is a limit of 10 times that a regular domain user account may be used to join a computer to the domain.