Windows 10 Stop Code 0xC00021a stuck on "Preparing Automatic Repair"

[dtorres0205]

I shut down my PC a few days ago and received an error message that was on too shortly for me to read it. My PC was idling with a black screen so I turned it off. When I rebooted, I got the error code and idling on the "Preparing Automatic Repair" screen. I've tried rebooting, but all I get as idling on the logo or the repair screen. What do I do?

 

[Colif]

This issue arises when Windows is updated. So, after the update, it doesn’t boot to Windows and displays this blue screen of death along with error. There are two files that are the major cause of this error to appear. These files are listed below:-

winlogon.exe: As the name of the file represents, this file is responsible for the login and logout operations inside Windows. This file can be damaged due to mismatch of System Files or 3rd party softwares. If this file gets damaged, then this error causes the PC to boot to the Windows Login.

csrss.exe: The second file causing this error is Csrss.exe. This .exe file belongs to Microsoft server or client. So, this file can also be damaged resulting this error.

http://superuser.com/questions/1092141/windows-10-cannot-boot-0xc000021a-error

If its either of those files, you won't be getting into win 10 in a hurry.

On another PC, download the Windows 10 media creation tool and use it to make a win 10 installer on USB

change boot order in Bios so USB first, hdd second
boot from installer, on 2nd screen after languages, choose repair this pc, not install
choose troubleshoot
choose advanced
choose command prompt
type SFC /scannow and press enter

this may not work as it sometimes says it can't from outside windows.

try start up repair (though this same as auto repair so may just loop)
boot from installer
on screen after languages, choose repair this pc, not install.
choose troubleshoot
choose advanced
choose start up repair - this will scan PC and maybe fix this - will ask for logon info


If anything on PC you have to save, try: http://www.howtogeek.com/howto/windows-vista/use-ubuntu-live-cd-to-backup-files-from-your-dead-windows-computer/

try a reset once its all saved:
boot from installer
on screen after languages, choose repair this PC, not install.
choose reset pc
choose keep files/settings (can only hope whatever caused mistake isn't saved in settings) or wipe it all and just start afresh on win 10
Either choice, win 10 will restart and reinstall win 10