How to recover SA password on Microsoft SQL Server 2008 R2

When you are using MS SQL Server in mixed mode, it is very important that you know your SA password.

There can be different reasons you lost the password

Person who installed the SQL Server knows the password but has left the building.
You did not write down the password in your password file
Password file is lost
…

Steps to recover the SA password

Start SQL Server Configuration Manager
Stop the SQL services
Edit the properties of the SQL Service
Change the startup parameters of the SQL service by adding a –m; in front of the existing parameters
Start the SQL services. These are now running in Single User Mode.
Start CMD on tthe SQL server
Start the SQLCMD command. Now you will see following screen
Now we create a new user. Enter following commands
- CREATE LOGIN recovery WITH PASSWORD = ‘TopSecret 1′ (Remember SQL server has default strong password policy
- Go
  - Now this user is created
Now we grant the user a SYSADMIN roles using the same SQLCMD window.
- sp_addsrvrolemember ‘recovery’, ‘sysadmin’
- go
Stop the SQL service again
Change the SQL service properties back to the default settings
Start the SQL service again and use the new created login (recovery in my example)
Go via the security panel to the properties and change the password of the SA account.
Now write down the new SA password.