Setting the ‘At Startup’ Options in SQL Server Management Studio

When you connect to SQL Server using SQL Server Management Studio, by default it shows the Object Explorer.
You can change this default option in SQL Server Management Studio:
click Tools -> Options

Click: Environment / General

In the 'At Startup' drop down, choose one option from the drop down list and click OK.

SQL Server Management Studio must be restarted for this change to take effect.

You can choose between these options:

Open Object Explorer
Open New Query Window
Open Object Explorer and New Query
Open Object Explorer and Activity Monitor
Open Empty Environment