FAQ : How to change Authentication Mode in SQL Server 2005

Trying to connect to SQL Server instance using SQL Server Login (mixed mode Authentication ) when the server is actually configured for Windows authentication is a very common issue for a newbie. How to change authentication mode using Management Studio is as follows :-

• Open management Studio and connect to the server
• Right Click on the Server Name and select the properties
• Select Security Page in the left pane
• On Security page there are two options
o Windows Authentication
o SQL Server and Windows Authentication Mode
• Select whichever the mode you want and apply and close (OK)
• The authentication mode is read from the registry when SQL Server first
Starts up. Therefore, if you change the authentication mode, you must stop
and restart the SQL Server service for it to take effect.

NOTE : RESTART THE SERVICE AFTER THE CHANGE