Configuring SQL Authentication can be tricky at times, and this is a great article that goes over the two types of authentication in SQL. I find some programs interface better with direct SQL authentication when Windows Authentication fails for any reason.

Note: This article is taken from http://kb.gfi.com/articles/SkyNet_Article/How-to-configure-SQL-Server-2005-2008-to-accept-SQL-Authentication and all credit goes to them for the writing. I’m posting it here simply as a reference in case there _site changes the above link. _

Fix Authentication in GFI ReportCenter

In order to use SQL Server authentication, you must first configure your server using the steps below.

1. Right-click on the server node and select ‘Properties’
2. Select ‘Security’ from the left menu under ‘Select a page’
3. Under ‘Server Authentication’, select the ‘SQL Server and Windows Authentication mode option’
4. Click ‘OK’ to close the dialog
5. Right click on the server node and choose ‘Restart’ for the changes to take effect

SQL Server authentication login

1. In the server node expand ‘Security’ and ‘Logins’
2. Right click on the login name and select ‘Properties’
3. Enter a password and confirm the password for the login
4. Select ‘Status’ from the left menu under ‘Select a page’
5. Set the ‘Login’ option to ‘Enabled’
6. Click ‘OK’ to close the dialog

Once you have walked through configuring SQL authentication, you can now change your instance to the type you need.