1. A method for authenticating a user of an application executing at a front-end computer, the method comprising: under control of a logon computer, establishing an account for the user with an operating system executing on the logon computer, the account specifying credentials of the user that are available to the user, the credentials for authenticating access by the user to the account of the operating system; and granting the user access rights to one or more application resources wherein the operating system manages access to the resource; and under control of the front-end computer, receiving credentials from the user; sending a request to access the application resource managed by the logon computer using the received credentials receiving an indication of whether the resource was successfully accessed using the received credentials; and when the indication indicates that the resource was accessed successfully, indicating that the user is authenticated and authorized to access the resource.