The best practice for protecting your data files and log files is to ensure that they are protected by access control lists (ACLs). Set the ACLs on the directory root under which the files are created.
View or change the default locations for database files
In Object Explorer, right-click on your server and click Properties.
In the left panel on that Properties page, click the Database settings tab.
In Database default locations, view the current default locations for new data files and new log files. To change a default location, enter a new default pathname in the Data or Log field, or click the browse button to find and select a pathname.
NOTE: After changing the default locations, you must stop and start the SQL Server service to complete the change.