KVM Windows virtual machines and ACPI unattended shutdown: a recap

Written by Super User on . Posted in Virtualization

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ACPI results with registry or group policy changes

Ok, it is not a secret that Windows XP/2003 requires some changes to default configuration to be more ACPI-friendly. More specifically you need one of these two changes:

  • change the group policy "Shutdown: Allow system to be shut down without having to log on" to enabled
  • alternatively, you can directly alter the registry key "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system\shutdownwithoutlogon" setting it to 1

Please note that for WinXP and 2003, the group policy “Shutdown: Allow system to be shut down without having to log on” controls both the poweroff virtual button in the login screen and the ACPI shutdown/physical button. For Win7/2008+ ACPI shutdown is not linked to this setting.

Windows version Console OFF long idle (3) Console OFF Console ON Console login Terminal Server login Locked session
Windows XP no (5) yes yes yes no (1,4) no (1,4)
Windows 2003R2 yes (2) yes yes yes yes no
Windows 7 yes (2) yes yes yes yes no
Windows 2008R2 yes (2) yes yes yes yes no
Windows 2012R2 yes (2) yes yes yes yes no


  1. it requires manual console-based shutdown confirmation
  2. it require two ACPI shutdown events: the first one exits from the screensaver, the second one shutdown the machine
  3. long idle = login screen with screensaver or monitor sleep
  4. warning timeout not working on winxp: http://www.pcreview.co.uk/threads/how-to-disable-shutdown-warning-message.2688069/
  5. the screensaver is never exited, but as soon you move the mouse, a sudden shutdown happens
  6. Win7 / 2008R2 / 2012R2 do not appear to have a login screensaver by default. Rather they put monitor to sleep, by default. To enable login screensave, give a look at https://support.microsoft.com/en-us/kb/185348

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