>When I installed SQL Server, I selected the default name of the server and instance. Is it possible to change that after?

My personal opinion would be to uninstall the instance and reinstall. I've done that a few times (where I didn't specify the instance name the way I wanted it...usually when I was creating a VM).

Now, there are system stored procs sp_dropserver and sp_addserver. They are discussed in these two links:

http://stackoverflow.com/questions/907851/change-sql-server-instance-name
http://stackoverflow.com/questions/12676627/renaming-a-sql-server-with-installed-named-instances

I have not tried these, so I can't vouch for whether they work. Maybe someone who has done this can jump in with their experiences.

But where I've had it happen to me, I just uninstalled and reinstalled.