Changing SQL Server Instance Name after renaming the physical machine or virtual machine

After a long timeout, I have decided to register something that I learned today.

Here is the scenario.

There is a named SQL Server instance running on a virtual machine. An Image of the entire machine was taken and restored with a different virtual machine name. (This was done as an exercise to create a new staging environment as a look a like copy of the production environment).

After the new virtual machine was created, there is a  named SQL Server instance is now running on the new virtual machine. But the @@SERVERNAME property is still displaying the old machine name.

Here is what you do to change the @@SERVERNAME property.

sp_dropserver  'OLD_HOST_NAME\INSTANCE_NAME'

sp_addserver @server = 'NEW_HOST_NAME\INSTANCE_NAME', @local = 'local'

Restart the SQL Server Instance using SQL Server configuration Manager.

Now execute SELECT @@SERVERNAME or 
                    SELECT SERVERPROPERTY('SERVERNAME')

You will notice that the new host name is displayed correctly.