Hopefully this is the right place to be asking this question, I'm desperate so any help is appreciated anyway.

My work computer is currently stuck in a blue screen reboot loop displaying error 0xc000021a. So far everything I have tried hasn't fixed it.

I believe this has happened by an update for Windows 10 which I have been getting notifications to install for a long time. Last night we had a power cut and I left my PC on the login screen so I think it may have automatically installed the update.

The error is something to do with the windows login service or cross.exe from what I have read.

I have tried: going back to a restore point, all restore points have now vanished. Running SFC /scannow. Booting in safe mode. Disabling driver signature enforcement. Startup repair. Resetting windows.

All of these lead to errors and the PC booting back to that same bluescreen loop.

What can I do?!

  • Are you able to pull the disk, put it in another machine to copy your data off, and then start again with that disk with a fresh install of Windows? Also, try this post as it has some other ideas to try out superuser.com/questions/239319/… – spikey_richie Dec 29 '17 at 11:25
  • That's what I'm just doing now, it seems like it's the only option unfortunately – Edward144 Dec 29 '17 at 11:28

I've faced this issue before. It's one of the blue screen of death errors. Im sharing 5 steps that will help you fix Error 0xc000021a

One of the following step will sort out the problem:

  1. Repair corrupted system
  2. Boot window manually
  3. Resetting computer's BIOS
  4. DO SFC scan
  5. Troubleshoot to fix automatically

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