Failure audits appear in the Security log within Event Viewer. The error appears as follows:
Login failed for user 'username'. The user is not associated with a trusted SQL Server connection. (Microsoft SQL Server, Error: 18452)
Mixed Mode authentication is not enabled on the SQL database server.
Enabled Mixed Mode authentication on the SQL database server.
To check or change the SQL authentication mode
Open the SQL Server Enterprise Manager (Start > Programs > Microsoft SQL Server > Enterprise Manager).
Right-click the SQL Server group you want to configure.
Click the Security tab.
Under Authentication, select SQL Server and Windows.