Microsoft SQL Server can present some unique challenges. This page shows two common issues that may prevent you from obtaining connectivity to your database server.
SQL Server and Windows Authentication
Make sure that Server Authentication is set to SQL Server and Windows Authentication mode (in SQL Server Management Studio, right-click on server, select Properties):
Set the port number
Make sure that TCP/IP is enabled in SQL Server Configuration Manager, and that IP6 and IPAll (ignore the other ports, e.g. IP1, IP2, etc...) have an assigned TCP Port (note: this is TCP Port, not TCP Dynamic Ports).
Important - restart the service
If you had to make any changes, you will have to restart the SQL Server service.
The port you specified in step 2 (normally 1433) will be the one to use when connecting to the database.