the user has initiated. Availability requests are not appropriate for preventing display power management during display of an animated advertisement. Temporarily Delay Automatic Sleep To help reduce system power consumption, Windows automatically places the computer in the sleep state after a period of user inactivity. Sleep consumes much less power than in the working state, allowing for large potential power savings when the system is idle. Typically, the computer automatically enters sleep after 30 or 60 minutes of user inactivity. The user can increase or decrease the sleep idle timeout in Power Options. Applications typically might need to prevent automatic sleep when they are consuming system resources to deliver a user scenario, but the user is not currently interacting with the system. Common scenarios include: Delivering a full-screen presentation Viewing video content Saving files to an optical disk Downloading files from the Internet or another computer on the network Recording television content However, when preventing automatic sleep, developers should keep in mind the large potential power savings for automatic sleep. The user or system administrator expects the system to automatically enter sleep after the period of inactivity specified in Power Options. Developers must ensure that their applications are delivering critical user scenarios when creating availability requests to prevent automatic sleep. Enable Away Mode You can also use availability requests to enable Away Mode on Windows Vista and later versions of Windows. Away Mode is designed for entertainment and media PCs. When Away Mode is enabled, if the user places the system in sleep, the computer remains on (ACPI S0 state) and the display is turned off and audio is muted. Away Mode provides the illusion that the system turned off, while it remains powered on to deliver media content to networked PCs or Windows Media Center Extender devices. Enable Away Mode only when essential for media and connected entertainment scenarios. End users expect the system to enter sleep when they select from Sleep the Windows Start menu or press the sleep button on the computer or a connected remote control. Similarly, use of automatic sleep and Wake-on-LAN technologies is often preferable to Away Mode because sleep provides greater energy efficiency than keeping the computer in the On state with Away Mode. New Functions for Availability Requests In previous versions of Windows, applications used the SetThreadExecutionState function to make an availability request to prevent display power management or prevent automatic sleep. SetThreadExecutionState requires that requests be set and cleared on the same Win32 thread. Additionally, SetThreadExecutionState callers cannot specify the reason for the availability request, which could aid administrators
the user has initiated. Availability requests are not appropriate for preventing display power management during display of an animated advertisement. Temporarily Delay Automatic Sleep To help reduce system power consumption, Windows automatically places the computer in the sleep state after a period of user inactivity. Sleep consumes much less power than in the working state, allowing for large potential power savings when the system is idle. Typically, the computer automatically enters sleep after 30 or 60 minutes of user inactivity. The user can increase or decrease the sleep idle timeout in Power Options. Applications typically might need to prevent automatic sleep when they are consuming system resources to deliver a user scenario, but the user is not currently interacting with the system. Common scenarios include: Delivering a full-screen presentation Viewing video content Saving files to an optical disk Downloading files from the Internet or another computer on the network Recording television content However, when preventing automatic sleep, developers should keep in mind the large potential power savings for automatic sleep. The user or system administrator expects the system to automatically enter sleep after the period of inactivity specified in Power Options. Developers must ensure that their applications are delivering critical user scenarios when creating availability requests to prevent automatic sleep. Enable Away Mode You can also use availability requests to enable Away Mode on Windows Vista and later versions of Windows. Away Mode is designed for entertainment and media PCs. When Away Mode is enabled, if the user places the system in sleep, the computer remains on (ACPI S0 state) and the display is turned off and audio is muted. Away Mode provides the illusion that the system turned off, while it remains powered on to deliver media content to networked PCs or Windows Media Center Extender devices. Enable Away Mode only when essential for media and connected entertainment scenarios. End users expect the system to enter sleep when they select Sleep from the Windows Start menu or press the sleep button on the computer or a connected remote control. Similarly, use of automatic sleep and Wake-on-LAN technologies is often preferable to Away Mode because sleep provides greater energy efficiency than keeping the computer in the On state with Away Mode. New Functions for Availability Requests In previous versions of Windows, applications used the SetThreadExecutionState function to make an availability request to prevent display power management or prevent automatic sleep. SetThreadExecutionState requires that requests be set and cleared on the same Win32 thread. Additionally, SetThreadExecutionState callers cannot specify the reason for the availability request, which could aid administrators
AvailabilityRequests.docx