https://stackoverflow.com/questions/4012526/trying-to-run-sqlcmd-fails-unable-to-establish-connection

http://v-consult.be/2011/05/26/recover-sa-password-microsoft-sql-server-2008-r2/

https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/connect-to-sql-server-when-system-administrators-are-locked-out