Post your bad power management-related app experiences here! RRS feed

  • General discussion


    If you discover a Windows Power Management-related issue with an application/service/driver that you would like to share with the world, you've come to the right place.  Bonus points for posting solutions or workarounds to the issues!

    We aren't looking for conjecture.  Only real, reproducible experiences associated with Windows Power Management.  Off topic posts, unsubstantiated reports and reports that are of generally poor tone (e.g. disparaging the vendor) will be deleted, no questions asked.  In short, please keep it factual and respectful.

    Use 'powercfg /requests' or 'powercfg /energy' in Windows 7 to help diagnose why your PC isn't automatically sleeping when it should or why your battery is draining faster than normal because system timer resolution has been set to 1ms by an application.  More information on the topic can be found at

    For each new report, REPLY TO THIS POST, and please include the following information.

    1) Vendor name, name of app, & version number (include web site link if vendor or app is not well known) and Windows OS version this is known to reproduce on

    2) Brief overview of the problem (one sentence)

    3) More detailed description of the problem, with repro steps if warranted.

    4) Workarounds/solutions (if any)

    If you have further useful information to share on a particular report, please REPLY TO THE POST THAT CONTAINS THE ORIGINAL REPORT (i.e. not this post).

    As an example I'll highlight a problem with an app that has a workaround (Microsoft worked with the vendor to fix the problem).


    Adobe Flash Player v10 (and earlier) on Windows 7/Vista/XP

    Flash Player prevents PC from automatically sleep after video is played and doesn't keep the display awake when actively playing video

    After playing video, Flash Player 10.0 leaves the audio channel open which in turn leaves the audio stack availability request in place and prevents a PC from automatically sleeping until the browser window containing Flash Player is closed.  This occurs when video ends naturally or is paused or stopped manually.  Also, Flash Player doesn't create a display availability request when rendering video, so the screen frequently dims or blanks if you aren't using the keyboard or mouse while watching video.

    The solution is to upgrade to Flash Player 10.1 from which fixes all of these issues and more.


    I I look forward to seeing the reports come in, whether they are for third party applications, Microsoft applications or built-in Windows applications/technologies. 



    Wednesday, October 20, 2010 8:34 PM

All replies

  • Microsoft, Windows Media Center, 6.1.7601.17514 (win7sp1_rtm.101119-1850), Windows 7 SP1 Home Premium 64 bit

    Media Center is not setting a system availability request when pausing live tv (i.e. the computer sleeps while live TV is paused). The expected behavior is that the computer stays on indefinitely when live tv is paused (note, this is different than for pausing videos or recorded tv, in which the expected behavior is to sleep on schedule after the pause is initiated).

    -I have a ceton infinitv tuner with cablecard. If you pause while watching live tv, the computer will sleep, causing you to loose the pause buffer.

    -When recording tv, "ehrec.exe" sets both a system and awaymode request (one for each program being recorded). The system will not sleep, either on schedule, or when the command for sleep is manually issued (it enters away mode as expected). When recording is over, the system sleeps on schedule.

    -When watching recorded tv, "ehshell.exe" sets a display and system request, and my audio driver (audio advantage micro) sets a system request. When pausing recorded tv, these 3 requests are cleared.

    -The requests when playing and pausing live tv are the same as for recorded tv

    -I have seen others report that, when watching live tv, "Legacy Kernel Caller" should set a request. The request should remain when pausing. Legacy Kernel Caller does not set a request under any scenario I have thought of on my system. 

    Thanks for any suggestions!

    Tuesday, April 10, 2012 2:52 AM
  • both Powercfg.exe and Control Panel Power Options claim they work with ACPI processor performance states (P-states). in theory it's possible to detect P-states with WDK pwrtest.exe /info:ppmperf (Admin rights are required) or run simple VBScript like below (no Admin)

    Const wbemCimtypeUint64    = 21
    On Error Resume Next
    Set col = GetObject("winmgmts:\\.\root\WMI").InstancesOf("KernelPerfStates")
    for each o in col
        WSH.Echo ""
        WSH.Echo "----"
    for each p in o.Properties_
        if IsNull(p.Value) then
            WSH.Echo p.Name
            if IsArray(p.Value) then
                Call States(p.Value)
                WSH.Echo p.Name & ": " & p.Value
            end if
        end if
    Sub States(arr)
    On Error Resume Next
    c = -1
    for each s in arr
        c = c + 1
        WSH.Echo "  -- P" & c
    for each p in s.Properties_
        if IsNull(p.Value) then
            WSH.Echo p.Name
            if IsArray(p.Value) then
                WSH.Echo "  " & p.Name & ": " & Join(p.Value, ",")
            if p.CIMType = wbemCimtypeUint64 then
                r = p.Value - CLng(p.Value / &H10000) * &H10000 ' Mod bug fixup
                WSH.Echo "  " & p.Name & ": 0x" & Hex((p.Value / &H10000)) & Hex(r)', p.Value
                WSH.Echo "  " & p.Name & ": " & p.Value ', p.CIMType
            end if
            end if
        end if
        WSH.Echo "  --"
    End Sub
    if Err <> 0 then
        WSH.Echo ""
        WSH.Echo "Error:", Hex(Err.Number), "-", Err.Description
    end if

    the theory works pretty good with AMD K8+ processors showing 3 P-states or more. when you work on Intel Core-based system it shows nothing. none ACPI P-stated are detected with Intel Sandy Bridge processor, for example. but Power Options still claims it works with ACPI performance states.

    could you smart guys form Microsoft explain this phenomena, please?


    • Edited by constm Sunday, June 2, 2013 12:09 PM
    Sunday, June 2, 2013 11:52 AM
  • never mind. root\WMI\ProcessorStatus works!

    as far as I understand KernelPerfStates was disabled because of KernelPerfStates.State.Control field (Intel Nehalem+ processors do not allow to change VID value any more).

    • Edited by constm Sunday, June 2, 2013 7:12 PM
    Sunday, June 2, 2013 7:11 PM