I just like to describe here that how can you change the SQL server Authentication?
It is very simple to do this, just go through following .
1. Log on into the server through Microsoft Sql-server Management Studio,
2. Right click on the Server.
3. Select Properties from menu.
4. Now you will find this Screen
5. And now check the radio button which you want.
Note: Be sure you have logins according to login mode, before changing the mode of SQL server Authentication.