0xc000021a
STATUS_SYSTEM_PROCESS_TERMINATED
What it means
A core user-mode process (winlogon or csrss) crashed during startup.
Common causes
- A failed update or driver
- Damaged system files
- Third-party software that hooks into login
How to fix it
- Open Recovery > Advanced options > Uninstall Updates and remove the latest quality update.
- Try Startup Settings > Safe Mode and uninstall recently added software.
- Use System Restore.