How to login to publishing sites

I have site collection with publishing feature turned on and anonymous access allowed, of course. But, I have one user who is administrator, so he needs to log in to the application, i.e. he needs to access "_layouts/settings.aspx" page. But, the problem is when he writes url http://myserver/_layouts/settings.aspx" he gets 403 forbidden message. In this case I would like that SharePoint asks for credentials and then allows him to access settings page (if he has permissions) instead giving 403 message by default. How can I do that?