Hi all, We have SQL Server default instance running on windows 2000 advanced server with both sql server executables and database files stored on local hard disk [raid 1 enabled]. As part of creating cluster environment, we have installed Microsoft cluster services with SAN as shared resource and tested it thoroughly. Now to upgrade current default instance to cluster instance we ran the SQL server 2000 setup. But the option 'Upgrading existing default installation to cluster installation' is disabled. What might be the problem?