When installing SCCM (SP2) and connecting to a remote SQL 2008 R2 (EE), you can receive an error: ‘Could not connect or execute SQL query’
This happens because of the installation of SQL 2008, which disables the SQL Server Browser service on the SQL server. Reset the server to Automatic and start the service.
After that you have to run the following command on the SCCM server: setspn -A MSSQLSvc/<FQDN of SQL Server> <DomainUser Name>.
Then as final step we must enable the Named Pipes and TCP/IP protocols in the SQL Server Configuration Manager. Open the SQL Server Configuration Manager, go to the SQL Network Configuration, Protocols for MSSQLSERVER and enable the Named Pipes and TCP/IP protocols, restart the SQL Server service and voila.