Login failed for user ‘NT AUTHORITY\NETWORK SERVICE’

After our server people did some MS SQL database restores from some old backups to find some data, some .NET websites we had on the server started showing an error. (note I couldn’t see the error and had to disable custom errors from remote only, see here http://tech.ralpharama.co.uk/1/viewing-errors-remote-machine-after-sql-restores-broke-sites Server Error in '/' Application. Cannot open database... » read more