After Installing new instance of SQL Server 2005 I run into a problem with logon exception "Login failed for user 'username'. The user is not associated with a trusted SQL Server connection. (Microsoft SQL Server, Error: 18452)". After googling on Internet I found a couple of links, which explain and show how to solve a problem.
- Microsoft Knowledge Base - Microsoft SQL Server, Error: 18452
- MSDN - How to: Change Server Authentication Mode
This exception happens when SQL server was configured to operate in "Windows Authentication Mode (Windows Authentication)" and doesn't allow
the use of SQL accounts. To fix it change the Authentication Mode of the SQL server from "Windows Authentication Mode (Windows Authentication)"
to "Mixed Mode (Windows Authentication and SQL Server Authentication)".