Is it possible to rename an SQL Server 2005 instance

I would like to change the name of my SQL Server instance. Is there a simple way of doing this or is a significant effort required? Note, this is a named instance - not the default instance.

Can a SQL Server instance be renamed?

SQL Server does not support renaming computers that are involved in replication, except when you use log shipping with replication. The secondary computer in log shipping can be renamed if the primary computer is permanently lost.

Can I rename a SQL Server database?

If you are using SQL Server, you can set the database to single-user mode to close any open connections and prevent other users from connecting while you are changing the database name. In Object Explorer, expand Databases, right-click the database to rename, and then select Rename.

Can you rename an instance?

you cannot rename an instance.

The only way is a reinstall. See this similar thread for more info: SQL Server, convert a named instance to default instance?