Windows system idle condition

Question

I'm looking that there are some tasks that are embedded with Windows that runs when system goes to idle state (such as Scheduled Defrag, System Restore, DefenderScan and RegistryBackup).

However, even if I leave the system stopped for such as 3 or 4 minutes, I don't see any of there tasks start to running them job.

What are the criteria that Windows uses to put the system state on idle?

Answer 1

The SYSTEM_POWER_POLICY structure contains an IdleTimeout field and an IdleSensitivity field, each of which are as described as I've copied below:

IdleTimeout: The time that the level of system activity must remain below the idle detection threshold before the system idle timer expires, in seconds.

IdleSensitivity: The level of system activity that defines the threshold for idle detection, expressed as a percentage.

So it means as long as the system activity is below IdleSensitivity for at least a period of time equal to IdleTimeout, it is considered idle.

How you actually read/write those values without writing a program, I have no idea, sorry. :(

Answer 2

There's a DWORD in the registry at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SchedulingAgent\MinutesBeforeIdle. Its default value is 15.

There's also a command to force idle tasks to run:

rundll32.exe advapi32.dll,ProcessIdleTasks