An operating system registry contains multiple "identities." One of these identities is designated the current identity. An application executing on a multitasking computer system uses information stored in the current identity to configure the application, for example to provide a user-specific user interface. When an application opens, it registers with an identity manager using objects known as "connection points." To switch identities, a user supplies the name of an identity to switch to. The identity manager then uses the registered connection points to query each of the applications for permission to switch identities. If all the registered connection points grant permission to switch identities, then the identity manager switches the current identity by changing information in the registry. The identity manager then notifies all applications, via their registered connection points, that a change to the registry has been made so that the applications can take appropriate action.