====== SQL Server: Restore Sysadmin Access ======

This guide explains how to regain `sysadmin` privileges in SQL Server using `sqlcmd` and single-user mode.

===== Steps =====

=== 1. Stop SQL Server service ===

On the host machine:

  net stop MSSQLSERVER

(Replace `MSSQLSERVER` with your instance name if not default.)

=== 2. Start SQL Server in single-user mode ===

Launch from an elevated command prompt:

  cd "C:\Program Files\Microsoft SQL Server\MSSQL15.MSSQLSERVER\MSSQL\Binn\"
  .\sqlservr -m

*Adjust the path to your instance version and install location.*

Leave this window running.

=== 3. Open a new terminal and run `sqlcmd` ===

  sqlcmd -S localhost -E


=== 4. Create the login and assign sysadmin ===

<code sql>
CREATE LOGIN [MACHINE_NAME\Administrator] FROM WINDOWS;
GO
ALTER SERVER ROLE [sysadmin] ADD MEMBER [MACHINE_NAME\Administrator];
GO
EXIT
</code>

Replace `MACHINE_NAME` with your actual computer name. You can confirm it with `whoami`.

=== 5. Restart SQL Server normally ===

In another terminal:

<code>
net stop MSSQLSERVER
net start MSSQLSERVER
</code>

You should now have full access using Windows Authentication.

===== Notes =====

<WRAP center round tip 60%>
Don’t forget the **GO** statements — each batch must be terminated for `sqlcmd` to execute it.
</WRAP>

  * Ensure only one connection is active in single-user mode, or the login may fail silently.