High Severity
0xc000021a Error: Windows Fatal System Error (BSOD)
Error 0xc000021a is a critical Blue Screen of Death (BSOD) error indicating that a crucial Windows system process has failed. Specifically, either csrss.exe (Client Server Runtime) or winlogon.exe has terminated unexpectedly. Windows cannot continue operating without these processes and forces a system halt to prevent data corruption.
Common Causes
- Corrupted csrss.exe or winlogon.exe system files
- Incompatible or corrupted system drivers
- Failed Windows Update leaving system in bad state
- Malware infection damaging critical system files
- Incompatible third-party software
- Registry corruption
- Hard drive failure or file system corruption
Symptoms
- Blue Screen of Death on startup
- Windows boot loop with BSOD
- System crashes immediately after login
- Cannot boot into Normal Mode
- Automatic Repair loop
- System shows STOP code 0xc000021a
How to Fix 0xc000021a
- Boot into Safe Mode and uninstall recent updates or drivers
- Run Startup Repair from Windows Recovery Environment
- Use System Restore to revert to a previous working state
- Run SFC /scannow from Command Prompt in recovery mode
- Run DISM /RestoreHealth from recovery command prompt
- Perform a clean boot to identify conflicting software
- As a last resort, perform an in-place repair install of Windows
What Is Error
Error code 0xc000021a is a Windows HRESULT error code that translates to "Windows Fatal System Error (BSOD)". HRESULT codes are hexadecimal values used throughout the Windows operating system to indicate specific error conditions. When you see this error, it means Windows or an application encountered the condition described above and could not continue the operation.
The error code format breaks down as follows: the leading 0x8 indicates a failure, the next digits identify the facility (the Windows subsystem that generated the error), and the remaining digits specify the exact error condition.
How Serious Is
Error 0xc000021a is a serious issue that should be addressed immediately. If you are experiencing a Blue Screen of Death, your computer may be unstable and data loss is possible. Back up important files as soon as you can access the system, and work through the fixes below before continuing normal use.