Ctrl + N key is used to open new query window in SQL Server. It is not working in SQL Server 2008. To enable this we have to change the keyboard layout to “SQL Server 2000” and then back to “Standard” and that will restore the default keyboard mappings.
To change the keyboard mappings, select Tools->Options from the SSMS menu and then go to Environment->Keyboard. From that spot, you can change the keyboard layout. Change the layout and press the “Ok” button to save the changes. Then, repeat the steps and select the standard layout and press “Ok” again. That will set the default keyboard mappings, which will include the Ctrl-N mapping.