How to empty or reduce the size of the Windows Update Log?

Discussion in 'Update Services' started by Bruce Sanderson, Jul 18, 2009.

  1. I notice that the Windows Update Log (%systemroot%\WindowsUpdate.log) on
    client computers is big and has records going back several years. This
    makes it slow to open and view current entries to diagnose problems.

    If I try and delete it, or open it in Notepad, delete some records, then
    attempt to Save it, I get told that the file is in use by another process so
    it can't be deleted (or renamed) or saved.

    Is there a way to delete, rename or reduce the size of this log file?
     
    Bruce Sanderson, Jul 18, 2009
    #1
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  2. This is *extremely* abnormal.

    Yes.

    1. Stop the Automatic Updates service. (net stop wuauserv)

    2. Delete the entire logfile (delete %windir%\WindowsUpdate.log)

    3. Restart the Automatic Updates service (net start wuauserv)

    The logfile is supposed to be maintained by the WUAgent. It's a rotating log
    file and should auto-rotate approximately every 30 days or at 2MB size.

    However, if permissions got changed on the logfile, or some other scenario
    occurred that interfered with the default configuration, it's possible that
    the WUAgent was unable to clear the logfile. Deleting the file and allowing
    the WUAgent to recreate the file should resolve this issue.


    --
    Lawrence Garvin, M.S., MCITP:EA, MCDBA
    Principal/CTO, Onsite Technology Solutions, Houston, Texas
    Microsoft MVP - Software Distribution (2005-2009)

    MS WSUS Website: http://www.microsoft.com/wsus
    My MVP Profile: http://mvp.support.microsoft.com/profile/Lawrence.Garvin
     
    Lawrence Garvin [MVP], Jul 19, 2009
    #2
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  3. Thanks, Gavin.

    None of the Update logs I looked at are over 2 MB, but some are close to
    that.

    Most of them had entries several months old - e.g. going back to February or
    March, 2009.

    --
    Bruce Sanderson
    http://members.shaw.ca/bsanders

    It is perfectly useless to know the right answer to the wrong question.
     
    Bruce Sanderson, Aug 8, 2009
    #3
  4. This is as expected.
    Could be that I'm mistaken on the 30 days...

    Could also be that the retention rules have been changed between WUAgent
    versions...

    On my Win7 RC machine, the logfile is slightly < 2MB and goes back to
    6/12/09 (the installation date of the machine).

    On my Vista SP2 machine, the logfile is only 1.3MB and only goes back 30
    days (7/4/09).

    The Vista machine is running the WSUS2SP2 RC v7.4 WUAgent; the Win7 RC
    machine is running the Win7 native v7.3 WUAgent (not sure why it's not
    selfupdated from my WSUS2SP2 RC server to the v7.4 WUAgent -- but it says no
    selfupdate needed -- Interesting).

    I also have a WinXP machine running the RC v7.4 WUAgent, and it has a 1.5MB
    logfile going back to June 29th, which is the creation date of that logfile.

    So maybe there's something unique going on in the Vista environment that's
    truncating the log at 30 days, but not on other platforms.


    --
    Lawrence Garvin, M.S., MCITP:EA, MCDBA
    Principal/CTO, Onsite Technology Solutions, Houston, Texas
    Microsoft MVP - Software Distribution (2005-2009)

    MS WSUS Website: http://www.microsoft.com/wsus
    My MVP Profile: http://mvp.support.microsoft.com/profile/Lawrence.Garvin
     
    Lawrence Garvin [MVP], Aug 8, 2009
    #4
  5. Bruce Sanderson

    halukanlar Guest

    Hi,

    I also have a problem with the windowsupdate.log file. We have a server with an application that serves handhelds at our factory. These handhelds are windows mobile and connect via terminal services.

    When I check the servers \users\ directory under each handhelds directory there is a windowsupdate.log file and the file sizes vary from a few megabytes to over 100MB.

    I regularly have to manually delete these log files to clear up some space on the server.

    Can you advise?

    Thanks,
    Haluk
     
    halukanlar, Dec 22, 2013
    #5
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