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How do I reinstall windows 8 with CMD and invalid media?

Anonymous
2015-11-09T02:28:41+00:00

Hello everyone!

I recently have been unable to boot up my computer due to a 0XC000021A error. I believe that the error originates with my Windows download, which i bought a disk for. I then upgraded to windows 8. Now, seeing that i cannot start in safe mode, nor perform any sort of boot up, i am restricted to either CMD console commands and a windows 8 disc. When i try to reinstall windows, i am told that my disk is considered faulty media and wont let me continue.

Any help on how to resolve my problem would be fantastic!

Windows for home | Previous Windows versions | Windows update

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Anonymous
2015-11-10T04:55:38+00:00

Hello Alexander,

Thank you for posting your question on Microsoft community.

I appreciate you for providing details about the issue and your efforts towards resolving it.

This issue may occur due to corrupt Windows startup files.

I would suggest you to run bootrec commands in the command prompt from Windows recovery environmentand check if it helps. Please follow these steps:

a. Do one of the following, depending on whether you have installation media (such as a DVD or USB flash drive):

  • If you have installation media for Windows 8.1, start (or boot) your computer from the installation media. Insert the DVD or USB flash drive and restart your computer. If you see a message asking you to "Press any key to boot from DVD", do so. If you don’t see the message, you might need to change the boot order in your computer's BIOS settings so that it first starts from the DVD or USB. When you see the "Install Windows" page, click "Repair your computer" to start the Windows recovery environment.
  • If you don’t have installation media, use the power button to restart your computer three times. This will start the Windows recovery environment.

b. In the Windows recovery environment, on the "Choose an option" screen, click "Troubleshoot".

c. Click "Advanced options" and then click "Command prompt".

d. In the command prompt, type the following commands one by one and press Enter after each command.

bootrec /fixmbr

bootrec /fixboot

bootrec /rebuildbcd

Note: Modifying BIOS/ complementary metal oxide semiconductor (CMOS) settings incorrectly can cause serious problems that may prevent your computer from booting properly. Microsoft cannot guarantee that any problems resulting from the configuring of BIOS/CMOS settings can be solved. Modifications of the settings are at your own risk.

I hope this information helps.

Please do let us know if you need any further assistance.

Thank you

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  1. Anonymous
    2016-10-04T21:22:47+00:00

    I have same problem on Nextbook tablet. Came with windows 8 but had upgraded to 10. after running boorec it says I have no windows installations.  What is going on?  And how can I boot from a MicroSD card since I cant access bootmgr and the one time I did my onscreen keyboard wouldn't come up.

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  2. Anonymous
    2015-11-09T13:25:19+00:00

    Hello everyone!

    I am currently unable to use my computer. This is because every time i attempt to boot up, i get the error message 0XC000021A and my computer attempts to repair itself. This does not work and every attempt to use the pre-boot repair options results in a loop back to the repair screen.

    The worrying thing is that when i attempt to use the windows 8 disc to reinstall windows, i get told that my disc is invalid media. I think this might be because im using windows 8.1 and its a different OS, but i might be wrong.

    The only piece of computer enabled technilogy i have is my phone. I cannot create any backup media or install media. The only options i can see are to use command prompt to either do a complete factory restore or to tell my computer that the disc is not invalid

    Any help on what to do to get my computer back would be awesome.

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  3. Anonymous
    2015-11-09T03:50:49+00:00

    Hi, thanks for the speedy response.

    There is a typo on my origional question. What i meant is that i bought a windows 8 disc and then upgraded to windows 8.1 using the internet. Sorry for the confusion.

    I am very limited by my choices right now. I cannot create any backup media because i only have access to pre-boot content. When i try to boot i get looped back to a windows 8 repair screen.

    Additionaly, i dont have access to a fully functioning computer, therefore i cannot create installation media.

    I believe that my only option is to somehow use command prompt to tell my computer, which is currently using windows 8.1, that my windows 8 disc is useable. 

    Any additional help would be great.

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  4. Anonymous
    2015-11-09T02:38:54+00:00

    Hello everyone!

    I recently have been unable to boot up my computer due to a 0XC000021A error. I believe that the error originates with my Windows download, which i bought a disk for. I then upgraded to windows 8. Now, seeing that i cannot start in safe mode, nor perform any sort of boot up, i am restricted to either CMD console commands and a windows 8 disc. When i try to reinstall windows, i am told that my disk is considered faulty media and wont let me continue.

    Any help on how to resolve my problem would be fantastic!

    Hi,

    You upgraded to 8 from what?

    If you upgraded, you have to reinstall the original OS > then do the Upgrade.

    Microsoft has 8.1 Media freely available.

    "Create installation media for Windows 8.1"

    http://windows.microsoft.com/en-us/windows-8/create-reset-refresh-media

    A similar Tutorial which may also assist you

    "Create Installation Media for Windows 8.1"

    http://winsupersite.com/windows-8/create-installation-media-windows-81

    In the first screen of this very simple wizard, you need to choose the following:

    Language. English – en-us if you're in the United States.

    Edition. Windows 8.1 (Core), Windows 8.1 N, Windows 8.1 Pro, Windows 8.1 Pro N, or Windows 8.1 Single Language.

    Architecture. 64-bit (x64 ) or 32-bit (x86).

    _______________________________________

    "How to Create a Bootable USB or DVD with a Windows 8 or 8.1 ISO"

    http://www.eightforums.com/tutorials/2227-create-bootable-usb-dvd-windows-8-iso.html

       Warning

    This will not work to install Windows 8 or 8.1 for UEFI. For that, see this tutorial below instead.

    UEFI Bootable USB Flash Drive - Create in Windows

    Cheers.

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