Add BUILTIN\Administrators group in SQL and add sysadmin role

Setup: SQL 2008, SQL 2008 R2 or SQL 2012 fresh install

Problem: After default installation of SQL, the BUILTIN\Administrators group is not granted any permissions on SQL

Solution: Open the SQL Management Studio and run the following commands:

EXEC sp_grantlogin 'BUILTIN\Administrators'
EXEC sp_addsrvrolemember 'BUILTIN\Administrators','sysadmin'