Cannot install Exchange 2000 or Exchange 2003 in an Exchange 5.5 site

When you attempt to install Microsoft Exchange 2000 Server or Microsoft Exchange Server 2003 for the first time in an existing Microsoft Exchange Server 5.5 site, the installation may not finish successfully. You may receive the following error message:

This problem can occur if you previously attempted to install Exchange 2000 or Exchange 2003 in the site, but the installation did not finish successfully. If you completely remove the server from the Exchange Server organization and the Microsoft Windows 2000 Server domain, Windows 2000 Server Active Directory may still contain links to the deleted public information store. When you attempt to install Exchange 2000 or Exchange 2003 again, these invalid links prevent the installation from finishing successfully.

To resolve this issue, run Update.exe with the /removeorg switch. For additional information about how to run Update.exe with the /removeorg switch, click the following article number to view the article in the Microsoft Knowledge Base:

Warning The /removeorg option removes all Exchange organization information, such as administrative groups, routing groups, and server objects, from the configuration naming context in Active Directory.

Important Do not use the /removeorg option unless you intend to remove Exchange completely from your organization. You must also remove Exchange from your servers before you run the /removeorg option. The /removeorg option removes all servers that are running Exchange 2000 and Exchange 2003 from your organization. Servers in your organization that are running Exchange 2000 and Exchange 2003 will not function after you run this option. If this option is used unintentionally, you may have to reinstall all the servers in your organization that are running Exchange 2000 or Exchange 2003. Make sure that you have moved any Exchange mailboxes that you want to move from the servers that are running Exchange before you perform this procedure.