See how to recover SQL Server SA password when lost or forgot it and the SA account is locked out. Introduce methods to SA password recovery depending on whether Windows Authentication is available.

1. Recover Lost SA Password for SQL Server
Forgot/Lost SQL Server sa password? Locked out of SQL Server
SA account? Cannot connect to SQL Server?
If you encounter the above problems, find solutions to recover
lost SA password instead of rushing to reinstall your SQL Server.
Actually, logging to SQL Server with Windows Authentication
can recover SA password. When the SA password recovery is
performed successfully, you can switch to SQL Server
Authentication. Now, see how to recover SA password
depending on whether you can login to SQL Server with
Windows Authentication.
1. When you still can login with Windows Authentication
If you still can connect to server with Windows Authentication,
just open SQL Server Management Studio to recover SQL
Server SA password.
Step 1: Open SQL Server Management studio.
Step 2: Connect to server with Windows Authentication mode.
Step 3: In Object Explorer, expand the root folder. Go to
Security -> Logins -> sa.

2. Step 4: Double click on the sa account to open Login Properties
dialog.
Step 5: Select General page. Change the sa password.

3. Click OK to save changes. Then you have recovered your sa user.
2. When you failed to login with Windows Authentication
If you failed to connect to server with Windows Authentication,
use SQL Password Geeker to recover SQL Server sa password.
Important: SQL Password Geeker is easy-to-use third party
software, with which you can view all SQL Server users
including the SA user. So you can select any one user to recover
its password. It supports to recover SA user or other users
passwords for Microsoft SQL Server 2005/2008/2012/2014.

4. Step 1: Download and install SQL Password Geeker on your PC.
Step 2: Stop SQL Server service. (Open SQL Server
Configuration Manager to stop services)
Note: This step is critical before you start to recover SQL Server
SA password.
Step 3: Launch SQL Password Geeker. Click on Open File button.
Go to the disk where your SQL Server is installed and navigate
to the path Program FilesMicrosoft SQL
ServerMSSQL.1MSSQLDatamaster.mdf. Select the
master.mdf file and click Open button to import it into SQL
Password Geeker.

5. Note: Once the master.mdf file is imported in SQL Password
Geeker, as you can see, all users should be displayed and you
can select any one user to recover its password.
Step 4: Select the sa user. Click on Reset button.

6. Step 5: Type a new password for your sa account. Click OK to
save changes.
A dialog saying “Password successfully changed” immediately
pops up. It means you have successfully recovered your lost
SQL Server sa password.
Related:
Forgot SQL Server 2008 SA Password How to Connect?