STOP: c000021a (Fatal System Error) Error

The following error message may be displayed on your Microsoft Windows Server 2003 (Standard Edition (32-bit x86), Datacenter Edition (32-bit x86), Enterprise Edition (32-bit x86) and Web Edition, or Microsoft Windows XP (Professional, Media Center Edition, Tablet PC Edition) computer:

STOP: c000021a {Fatal System Error}
The Windows Logon Process system process terminated unexpectedly with a status of 0xc0000034 (0x00000000 0x0000000)
The system has been shutdown.

Note: In the error message, the parameters given in the parentheses depend on your system’s configuration. Additionally, different parameters may display in different occurrences of the error message.

Cause of the Error

The STOP: c000021a (Fatal System Error) error occurs when the Windows NT kernel detects that either Winlogon.exe or Csrss.exe processes has failed. When this happens, the Windows NT kernel stops the system and generates the stop error message.

Although there can be many causes of this problem, some of the most common causes are:

  • You have mismatched system files installed on the system.
  • A Service Pack installation failed to complete.
  • You recently restored a few files on the hard disk, but the process failed to correctly restore the files that where in use during the restoration.
  • You have an incompatible third-party software on your computer.

Resolution Methods

To resolve this issue, you first need to find out which of the two processes (Winlogon.exe or Csrss.exe) failed and the reason behind their failure.

To find out this information, you need to register Dr. Watson as the default debugger program-ideally, it should already be the default debugger for your system.

The Dr. Watson debugger program logs all information related to failed processes to the Drwtsn32.log file. In addition to this, the debugger program can be configured to create memory dump files related to the failed processes. You can refer these dump files to analyze the reason behind a process failure.

Perform the following steps to configure Dr. Watson as the default debugger program to record user-mode program errors:

  1. Open Start menu, select Run, type Drwtsn32.exe -I and then press Enter. This command sets Dr. Watson as the default debugger.
  2. Next, run the Drwtsn32.exe command.
  3. In the Dr. Watson for Windows dialog box, select the following check boxes:
    • Append to Existing Log File
    • Visual Notification
    • Create Crash Dump File
  4. Now, when your computer restarts after the STOP 0xC000021A error is generated, run the Dr. Watson command.
  5. Here, view the paths to the Dr. Watson and User.dmp logs.
  6. Open Windows Explorer, navigate to the log files and then open them.
  7. Here, check the cause behind the STOP 0xC000021A error.

Most of the time, this error occurs due to the failure of the Winlogon.exe process. This usually happens if a faulty third-party Graphical Identification and Authentication (GINA) DLL exists on your system. GINA is a replaceable DLL component that is used to perform the following tasks:

  • Implement the authentication policy of the interactive logon model.
  • Perform user interactions, such as authentication and identification.

At times, a remote control software may replace the default GINA DLL file, msgina.dll, on your computer and you may face the stop error. This is the reason why it is a good idea to first check if you have a third-party msgina.dll on your computer. To do this, run the regedit command to open the Registry Editor tool. Here, navigate to the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

Here, check if the value GinaDLL REG_SZ is on the right pane. If the value is there and its value is different from msgina.dll then it means that a third-party software has changed this value. In case this value is not there, it implies that that your system uses msgina.dll as the default DLL file for GINA.

If this error follows a new driver, service or third-party software installation, you must try to uninstall this new software to repair the error. To do this, you may use a good third-party program uninstaller tool, such as Perfect Uninstaller to ensure complete removal. You may also try to install an update for the software, if it is available.

You may also try to boot your computer with Last known good configuration information to see if the error goes. If nothing works, you may have to perform and in-place upgrade of your operating system to resolve the error.