KB10518: “Login failed for user ‘X’. Reason: not associated with a trusted SQL Server connection” error message appears when logging into a project source in MicroStrategy against Microsoft SQL Server.

SYMPTOM:
After configuring a metadata repository in SQL Server and creating a project source for this metadata, the user attempts to login and receives the following error:
 
Database error <>: Connect failed. Error type: Odbc error. Odbc operation attempted: SQLDriverConnect. Login failed for user '...'. Reason: Not associated with a trusted SQL Server connection. Driver's SQLSetConnectAttr failed
The ODBC DSN has been configured with a correct SQL Server login, as illustrated below:
 

 
CAUSE:
This error occurs because the ODBC DSN has been configured to use standard authentication ("login ID and password entered by the user"), while SQL Server is configured to accept only Windows NT authentication.
 
As a result, SQL Server receives a standard authentication login from the ODBC driver, and refuses the login because it is not a Windows NT network ID login request.
 
ACTION:
There are two ways to resolve this issue:
Configure SQL Server to accept standard authentication requests. To achieve this, perform the following:

• Launch the SQL Server Enterprise Manager.
• Right-click on the name of the database server affected and choose "Properties" from the menu.
• Click the "Security" tab. On this tab, choose "SQL Server and Windows" for the authentication option:
  

Alternately, the administrator may wish to configure the ODBC DSN to use Windows NT authentication:

 
Note: If NT authentication is desired, the administrator must ensure that an NT account exists within SQL Server for every user who will be accessing the project source directly. Metadata connections from the Strategy Intelligence Server will attempt to login using the Intelligence Server's service account. Two-tier connections, however, will use the NT network ID of the user who is currently logged into the machine. If this network account does not exist within SQL Server, the user will receive the "Not a trusted SQL Server connection" error message.
 
For this reason, using SQL Server standard authentication will simplify database administration and is probably preferable in most cases.
 
Third Party Software Installation:
WARNING:
The third-party product(s) discussed in this technical note is manufactured by vendors independent of Strategy. Strategy makes no warranty, express, implied or otherwise, regarding this product, including its performance or reliability.