When you create a trusted connection from Microsoft ASP.NET to Microsoft SQL Server, you may receive the following error message:
Login failed for user 'MachineName\ASPNET
For computers that run Internet Information Services (IIS) 6.0, you may receive the following error message: Login failed for user 'NT AUTHORITY\NETWORK SERVICE'
Note You receive either of these error messages specifically when you use integrated security (when you include the integrated security=sspi attribute in a connection string).