While executing CA Service Desk manager configuration, MSSql server is not listed.
SQL 2012 client is not installed in Service Desk Manager server, Installing SQL client in SDM server is a prerequisite, this will allow SDM to connect to the remote SQL database and then should show the "Microsoft SQL Server" database type in the list.
Further information about hardware and software prerequisites for SDM installation can be found in the link bellow:
1) Close sdci_MDB.exe and installation wizard
2) Install SQL client, including the connectivity, and SQL Tools like Management Studio in SDM Server using SQL Server installer/ISO. See an example in the following link:
How to install SQL Server Client Tools?
3) Run the installation wizard and sdci_MDB.exe to create the database. This time "Microsoft SQL Server" database type will appear in the list.