1809 install error

Discussion in 'Windows 10' started by Pasta88, Dec 15, 2018.

  1. Pasta88

    Pasta88 MDL Expert

    Jun 17, 2009
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    Hi Guys, I am trying to install windows 10 version 1809 update and I keep on getting this error of 0xc1420121. I turned off KIS2019 and malwarebytes. What am I doing wrong, plz?



    Thx
     
  2. kaljukass

    kaljukass MDL Guru

    Nov 26, 2012
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    #2 kaljukass, Dec 15, 2018
    Last edited: Dec 15, 2018
    Error 0xc1420121 is usually caused by
    • if Windows isn't in good condition, i.e. it is damaged
    • if you try to install an unsupported update
    • when the temp folders are full (You have never cleaned them)
    • if you use third-party antivirus programs that damage Windows's integrity
    PS! The heading is misleading, You have no problems with 1809 installing if it is already installed. So please correct the headline.
     
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  3. Pasta88

    Pasta88 MDL Expert

    Jun 17, 2009
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    Can I use windows repair tool to fix this?
     
  4. kaljukass

    kaljukass MDL Guru

    Nov 26, 2012
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    What tool?
    As long as we do not know, what is the reason, not possible recommend nothing.
    Maybe only remove those third party antivirus programs, clean all temp folder, check Windows and fix it if needed and then can try again.
    PS. what's the update which You tried to install and how You tried to install it? Did You used Windows update or something else?
     
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  5. Pasta88

    Pasta88 MDL Expert

    Jun 17, 2009
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    I updated my laptop without issues after I uninstalled KIS2019 and MBAM so maybe that is the issue. Just had windows firewall and defender.
     
  6. Mr.X

    Mr.X MDL Guru

    Jul 14, 2013
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    Sometimes AV/IS suites need to be uninstalled to stop any interference with the systems.
     
  7. coleoptere2007

    coleoptere2007 MDL Guru

    Apr 8, 2008
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    So it is not a clean install but an upgrade with KIS2019 active. I join Mr.X for this point. Do a clean install first.