Does anybody know or have a link to documentation on how the Power Manager of Windows, determines to go to the ACPI power states S1-S4? Are there any settings that can be configured? I know that by default states S1-S3 are disabled in Vista and later (they can be enabled by a group policy). Can Windows cycle through these states while for instance an application is actively running?
System Power States
To the user, the system appears to be either on or off. There are no other detectable states. However, the system supports multiple power states that correspond to the power states defined in the Advanced Configuration and Power Interface (ACPI) specification. The following table lists the power states from highest to lowest power consumption.