How to Connect to an MS SQL Server Named Instance
There are two ways to connect to a SQL Server database using a named instance.
The first option is to add the instance name after the database name in the "Add Connection Profile" screen. To do this, simply add a forward slash followed by the instance name after the database name, for example test\instance
The second option is to click the "Configure" button next to the "Conn. Properties" field in the "Add Connection Profile" screen. This will launch a new window. One of the options on the configure screen is called "instance". Type the instance name in the corresponding field and then click "Save".