Change SQL Server authentication mode using script

Question

I am wondering how can someone change the sqlserver authentication mode by just a script?

I need a script to run in query window and change the authentication to mixed mode with it. Any idea?

Answer 1

For Windows only mode:

EXEC xp_instance_regwrite N'HKEY_LOCAL_MACHINE', 
    N'Software\Microsoft\MSSQLServer\MSSQLServer', N'LoginMode', REG_DWORD, 1

Use 2 instead of 1 for mixed authentication.

You'll have to restart SQL Server after changing this setting. You can't do that from T-SQL. From the command prompt, it's something like net stop mssqlserver then net start mssqlserver.