There is a way to rename the default instance name using the application file;

c:\Program Files\Microsoft SQL Server\90\Tools\Binn\VSShell\Common7\IDE\ASInstanceRename.exe

I happened to encounter this error when trying to install SQL Analysis 2000 with existing SQL 2005 already installed but was not able to due to the instance naming conflicts. If you know a better way to work around it, do leave a comment.

I had been having the abovementioned problem (couldn’t even connect to my AS server using Management Studio on my local machine). I installed SP1 and all post SP1 hotfixes. Even this didn’t seem to help the problem. What DID help it was to check the accounts under which the relevant services were running:

1) Ensure the “SQL Server Browser” service is running under the Local System account (I previously was using a NETWORK SERVICE account – which was probably my own fiddling fault.).

2) My “Sql Server Analysis Services (InstanceName)” Service is also running as Local System.

And then it worked. Hooray!.