Recently I have got two desktop computers at home and both of them are very powerful machine.
Machine 1 : Windows Vista SP1 with SQL Server 2008
Machine 2 : Windows 2003 with SQL Server 2005 with SP2
When I was trying to connect from SQL Server 2008 to SQL Server 2005 using Windows Authentication I was getting following error.
Login failed for user ‘UserName’. The user is not associated with a trusted SQL Server connection.
To resolve this error follow the steps below on computer with SQL Server 2005.
Once above two steps are completed when connected from SQL Server 2008 to SQL Server 2005 using Windows Authentication it will connect successfully.
Reference : Pinal Dave (http://www.SQLAuthority.com)