Windows 10 pro only boots in Disable Driver Signature Enforcement and error 0xc000021a otherwise

Hi, 3 weeks ago after a Windows update I got a BSOD DPC watchdog violation issue while watching some videos on Youtube. I restarted the PC and checked the most recent update has to do with the NVIDIA driver. So I uninstalled the update. However the issue persisted. BSOD would appear after several minutes of loggin in. Then I uninstalled all my NVIDIA driver and BSOD still there. BSOD still appeared even in safe mode. I then used the installation media to boot and did a system restore. The restore failed saying I need to do chkdsk for my Windows drive which I did. The disk checking lasted for 2 days and failed to finish in stage 3. I then tried the Automatic Repair, waited another 3 days for the Repairing Disk Errors message which then turned to Scanning and Repairing Drive C for another 2 days. It stucked on 23% and the PC restarted and back to Repairing Disk Errors. I waited another week and the same cycle again. Scanning drive C for 2 days, stucked on 23% and restart. After that, I stopped the Automatic Repair loop with bcdedit. Then with every options in Advance startup options, BSOD would appear with 0xc000021a code, except when driver signature enforcement is disabled and the PC would boot to safe mode and I was able to log in. However now I'm stuck and dunno what to try next. I have tried the following things without any success :

1. Rebuild BCD

2. sfcscan

3. Copy previous registry in Regback folder

4. DISM restore health

5. Refresh PC

any suggestions would be greatly appreciated. Thank you



Thanks for following up. I missed the part when you mentioned that you already attempted to rebuild BCD and I apologize for that. Moving along, the next step that we can suggest is to use a different driver for the IDE ATA/ATAPI controller. Here are the steps:

  1. Go to Control panel > Hardware and Sound > Device manager.
  2. Open the IDE ATA/ATAPI controllers tab.
  3. Select the controller 'SATA AHCI,'  right click and select Properties.
  4. Choose the Driver tab and Driver Details and check if the driver found there is 'iastor.sys'.
  5. Select Update Driver Software, Browse and Let me Pick from a list of devices.
  6. Select 'Standard SATA AHCI Controller' from the list and install.
  7. Restart your PC.

This process was found to be a fix to the majority of reported WATCHDOG_VIOLATION errors in windows 10. If the issue still persist, we suggest updating all other drivers, especially your graphics card driver manually.

Please do let us know the outcome of this troubleshooting step.

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Question Info

Last updated June 11, 2021 Views 8,734 Applies to: