User logon failure, the user is not associated with a trusted SQL Server connection, error: 18452

This happens sometimes when you install SQLServer2005 (or the SQLServer2005 that comes with Visual Studio 2008) with SQL Server authentication:

The reason for this error is that when you install SQL Server, the logon method is restricted to Windows authentication, so the login error occurs when you log in with a detailed user, and the workaround is:

1. Right-click the properties of the login server after using Windows authentication.

2. Select "Security" to set ' Server Authentication ' to: SQL Server and Windows Authentication mode.

3. Restart the service, ok!

User logon failure, the user is not associated with a trusted SQL Server connection, error: 18452