Abstract: A method and system for authenticating access to heterogeneous computing services is provided. In a preferred embodiment, logon providers are configured into the computer system, which provide secure access to their services by requiring authentication of user identification information using a logon mechanism. According to this embodiment, a user designates a primary logon provider to provide an initial logon user interface. The user enters identification information when this user interface is displayed, for example a user name, a password and a domain. The computer system executes a logon sequence, which first invokes the primary logon provider to collect identification information and to authenticate the user for access to services provided by the primary logon provider. The system then authenticates the collected identification information to provide the user access to operating system computer services.