Hi, Jim Hong, Program Manager on UAC, here again to tell you about a new change in the UAC user experience coming in RC1. Applications that start when the user logs on and that require elevation are now blocked in the logon path.

Without blocking applications from prompting for elevation in the user's logon path, both standard users and administrators would have to respond to a User Account Control dialog box on every log on. While this potentially becomes an annoyance for administrators, it is an unusable UI for standard users who cannot drive the UAC elevation prompt without having an administrator around to provide credentials. Furthermore, we advise users to be wary of prompts that appear without them taking an explicit action -- and prompts generated at startup go against that advice.

In RC1 and later, Windows Vista notifies the user if an application has been blocked by placing an icon in the system tray and providing a notification balloon during the startup sequence. See Fig. 1 for a visual of what this might look like:

In many cases, users can operate their computers normally without the software that was skipped. However, in cases where the skipped application may be needed, users can then right-click this icon to run the applications that were blocked as they logged on. The user can elect to manage which startup applications are disabled or removed from this list by double-clicking the tray icon and bringing up the default application that controls Startup programs.

The areas where these applications are blocked from are:

• Per-user Startup Folder
• Per-user RUN Key
• Per-machine Startup Folder
• Per-machine RUN Key

Independent Software Vendors who wish to have part or all of their software suite run during the startup process are encouraged to architect their applications to run AsInvoker so that all users (that is, administrators and standard users) can run the software without the need for a UAC elevation.

A couple of exceptions to note: First, setup applications that need to complete their setup after a reboot should be putting their application in the RunOnce key. This key gets consumed by the next Administrator account that logs on, and the setup will continue without the need for an elevation. (This key can only be set by a program running with elevated privileges.) Second, applications that require UAC elevation that gets pushed out via the POLICY\RUN keys will not get blocked at logon. Therefore, they will run and will either result in the Secure Desktop prompt or appear in the taskbar as a blinking button that will require user input before the desktop switch occurs.

This feature will really help users with streamlining the logon path so that they can start using their Vista PCs quickly, with as little distraction as possible. Users maintain control of these UAC elevations. This reinforces the UAC theme of putting admin elevation under the user's control.