[SQL Server] how to modify Authentication Mode

The modification method with SQL Server Management studio is omitted. The following method is used to modify the registry:

In the Registry (usual location in SQL Server 2005 ):

HKLM \ SOFTWARE \ Microsoft SQL Server \ mssql.1 \ MSSQLServer \ loginmode

If the value is 0x00000001 (1), that means it is set for Windows authentication onLy. if you change the value to 0x00000002 (2), you're setting it for mixed mode. the next time SQL server starts, it will start up in mixed mode. this is a known "backdoor" to get into SQL Server, hence the advice to always secure the SA account with a strong password, even if the SQL Server is set for Windows authentication onLy.

Please refer to: http://www.sqlservercentral.com/Forums/Topic421197-149-1.aspx