Login failed for user "USERNAME-HERE." Reason: Not associated with a  trusted SQL Server connection.

This error most commonly occurs when using SQL authentication, rather than Windows Authentication. There are a few reasons to use SQL authentication rather than Windows:

• Client is not runnig a domain
• Network contains PC's running Windows98

To enable both authentication protocols:

1. Go to Enterprise Manager.
2. Right Click on Server Name
3. Select Properties
4. Go to Security Tab
5. Set authentication to SQL Server and Windows