Windows 10: Computer won't boot, get error 0xc000021a


  1. Posts : 5
    Windows 10 Was 8 then 8.1
       09 May 2017 #1

    Computer won't boot, get error 0xc000021a


    I went to use my computer this afternoon and it locked up and now I get "error 0X000021A" I have been unable to get it to boot into safe mode or anything else. It has an SSD and I have the original HD which I installed and the computer will boot to that. However it has windows 8 as the operating system. I had done the upgrades to 8.1 and 10 but they are not on the HD? Is there any way to get the windows 10 loaded again? If not, I will continue to get by with Windows 8. I can't get the log information because it won't boot up.
    CPeter
      My ComputerSystem Spec

  2. axe0's Avatar
    Posts : 13,605
    Windows 10 Pro
       10 May 2017 #2

    See if you can boot this Win10PE, if you can use HDTune and do the following please.



    Computer won't boot, get error  0xc000021a Diagnostics Test Computer won't boot, get error  0xc000021a
     HDD TEST

    Note   Note
    Run the tests on all hard drives/partitions!


    Note   Note
    Please run HDTune first, in the order posted!

    Run HDTune to
    • check the health,
    • scan for errors, no quick scan but full scan
    • run a benchmark.

    It may take some time, but please take the time you need to perform it properly.
    When above is done please make screenshots of the following
    • the health,
    • the error scan,
    • the benchmark incl. following
      • transfer rate,
      • access time,
      • burst rate,
      • cpu usage.
      My ComputersSystem Spec


  3. Posts : 5
    Windows 10 Was 8 then 8.1
    Thread Starter
       10 May 2017 #3

    So far I have been unable to boot from that disk either as a DVD or a thumb drive. Maybe this is the wrong place to ask this question, but can I reupgrade my Windows 8 HD to Windows 10. This is the HD that I took out when I cloned the SSD that is in there now. It will boot and run nicely on the HD, but it is Windows 8. I have all the rest of the software on the HD and there are very few files that were not on another computer on my network.

    CPeter
      My ComputerSystem Spec

  4. axe0's Avatar
    Posts : 13,605
    Windows 10 Pro
       11 May 2017 #4

    Could you describe what happens when you try to boot from a DVD or thumb drive
      My ComputersSystem Spec


  5. Posts : 5
    Windows 10 Was 8 then 8.1
    Thread Starter
       11 May 2017 #5

    When I try to boot from the DVD that I made from this site:
    Windows 10 Recovery Tools - Bootable Rescue Disk - Windows 10 Forums

    The DVD starts up and runs for a few seconds and then stops and it goes into the blue screens with the error message and starts the sequence of attempted repair, and ends up at the advanced options blue screen. I did go into the boot setup and set the DVD to the first one but that did not help. It still doesn't continue on the boot up from the DVD. Did I do something wrong or not do something I should have to allow it to boot from the DVD?

    I have the working HD which I can put in an external drive case and that is USB. I have not tried booting from that as USB, but it will boot when installed in the computer. It is Windows 8. If I can reupgrade to windows 10 on that drive I will be happy. Also, when I booted form the HD and plugged the SSD with Windows 10 in as an external USB drive, it showed up as drive "A" and it could not read it. It is possible the the SSD died and I should just forget that.

    I do appreciate your help and hope that we can resolve this problem.
    Peter
      My ComputerSystem Spec

  6. axe0's Avatar
    Posts : 13,605
    Windows 10 Pro
       11 May 2017 #6

    I've personally never seen a USB or DVD being used for booting when it is set on top of the boot list, rather you need to select it from the boot menu.
      My ComputersSystem Spec


  7. Posts : 5
    Windows 10 Was 8 then 8.1
    Thread Starter
       11 May 2017 #7

    Not to appear too ignorant but as I have three machines running Windows 7 Pro and this machine on 10, I don't know how to get to the boot menu in 10. That would probably be the answer. When I try to use the "boot menu" I get a message that says "system doesn't have USB or DVD boot option"
    Peter
      My ComputerSystem Spec

  8. axe0's Avatar
    Posts : 13,605
    Windows 10 Pro
       12 May 2017 #8

    The boot menu is independent of any OS, this menu should list all available boot options (hard drives, USBs and DVDs)
      My ComputersSystem Spec


  9. Posts : 5
    Windows 10 Was 8 then 8.1
    Thread Starter
       13 May 2017 #9

    I finally got the SSD to be read by my other computer. I started to do an error check and it locked up. I suspect that there is a fatal error on the SSD and think the safest thing to do is to move on. I may get another SSD and clone the working HD with Windows 8.1 to it and then do the upgrade to windows 10. I have found that as long as it is in the same computer that I can redo the upgrade at no cost. That way I will still have my stable, working HD to fall back on. This SSD is several years old and has been in two or three computers and if I remember correctly, may have had an issue some years ago and was formated and reloaded.

    Thank you for trying to help. I do appreciate it and it was a good try, but a new SSD will be larger and faster and they are less than that I paid for this one.

    Peter
      My ComputerSystem Spec

  10. Ztruker's Avatar
    Posts : 6,237
    Windows 10 Pro X64 17134.191
       13 May 2017 #10

    No need to install 8.1 first. Just use the latest Windows 10 Media Creation Tool to get the latest ISOP and clean install it. Since it waas previously activated, it will activate again with no problem.

    Download Windows 10
    Windows 10 - Clean Install
      My ComputersSystem Spec


 

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