How to Create a New Sysadmin Account in SQL Server Without Access to Existing Admins
In this guide, I’ll walk you through how to recover administrative access to SQL Server when no authorized accounts are available including how to enable the sa account or create new sysadmin-level logins. This method is especially useful in environments where SQL authentication settings have changed and applications like SCCM lose database connectivity.
Before proceeding, it’s critical to understand how your SQL Server’s authentication mode was originally configured. Changing it (e.g., switching between Windows Authentication and Mixed Mode) can break connections for applications that rely on SQL logins. In this post, I’ll show you how to add both Active Directory and SQL-based users without modifying the authentication mode keeping your environment stable.
Step 1: Enable Single-User Mode
Open SQL Server Configuration Manager and navigate to : SQL Server Services → SQL Server (MSSQLSERVER) → Properties. Go to the Startup Parametres tab and add “-m” parameter.
This will start SQL Server in Single-User Mode after a service restart.
Step 2: Connect Using SQLCMD
Open Command Prompt as Administrator and connect using: SQLCMD -Slocalhost
Step 3: Enable the SA Account (If Password Is Known)
If you know the sa password and just need to re-enable the account:
ALTER LOGIN sa ENABLE;
GO
Step 4: Create a New Sysadmin Login
If you don’t have access to sa, you can create a new SQL login with sysadmin privileges:
CREATE LOGIN NSA WITH PASSWORD = 'Password@123456*';
ALTER SERVER ROLE sysadmin ADD MEMBER NSA;
GO
Alternatively, you can add a Windows domain user:
CREATE LOGIN [domain\user] FROM WINDOWS;
GO
ALTER SERVER ROLE sysadmin ADD MEMBER [domain\user];
GO
Step 5: Exit Single-User Mode
Once the new accounts are created, restart the SQL Server service again and remove the -m parameter from the startup configuration.
You now have two new accounts with sysadmin privileges on your SQL Server. You can use either one to regain full administrative access and continue managing your environment securely.
