1.    01 Sep 2015 #1
    Join Date : Sep 2015
    Posts : 1
    windows 10

    windows error code oxc000021a

    Hello, hoping someone can help me out with this.

    I upgraded to W10 a few weeks ago from W7. All went well.

    Then 2 days ago i got the windows error code oxc000021a, and the computer wouldn't start. Couldn't get into safe mode, and repair didn't work either. Really annoying. I've had to reinstall windows 7. I can still see my windows 10 old install saved under windows.old.

    I don't have any option yet to re-upgrade to W10, despite putting all the updates on W7 again. What can I do to get W10 again and recover my data from windows.old?

    Any help greatly appreciated. Thanks!
      My System SpecsSystem Spec

  2.    02 Sep 2015 #2
    Join Date : Aug 2015
    Posts : 42
    Windows 10 pro

    Download Media Creation tool, Run it and Choose Upgrade this PC.

    This will upgrade your pc back to windows 10. You might want to delete windows.old Folder first.
      My System SpecsSystem Spec

  3.    02 Sep 2015 #3
    Join Date : Apr 2014
    Space coast of Florida
    Posts : 3,824
    Windows 10 Pro X64 14393.105

    Found this on one of the MS forums:

    In my case the problem was related to AVAST, even if you are not using it as your antivirus it may still be in your computer. You need to uninstall AVAST, but it won't work from the normal 'uninstall programs'. Check on google for how to uninstall AVAST and download the file called AVASTCLEAR. It will restart the computer in safe mode and perform the uninstall. That was it for me, I don't have the problem anymore.
      My System SpecsSystem Spec


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