If the SA password is unknown, or needs to be changed.
There is no way to do it from the SQL Server Management Studio, because the users with access to the database do not have the rights or privileges to change the password. And no other user account was added to be a sysadmin during the SQL installation process.
1- Go to the elevated command prompt window of the SQL server and type: osql –L
2- Copy the full name of SQL Server as showed in the example above and type:
OSQL -S insert_servername_here -E
3- Execute the following query: sp_password NULL, new_password, ’sa’
4- Type GO , hit Enter and close the command prompt window.
Open the SQL Server Management Studio Console and connect to the server using the sa account and the new password entered during the steps explained above.
