STOP: c000021a Error message

When you use a workstation with Win XP, you may receive the following error message:

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.

The STOP 0xC000021A error occurs when either Winlogon.exe or Csrss.exe fails. When the Windows NT kernel detects that either of these processes has stopped, it stops the system and raises the STOP 0xC000021A error. This error may have several causes. Among them are the following:

Mismatched system files have been installed.
A Service Pack installation has failed.
A backup program that is used to restore a hard disk did not correctly restore files that may have been in use.
An incompatible third-party program has been installed.

Sometimes, after you install Roxio GoBack (included with Norton System Works), and attempt to start your computer, you may receive an error message:

C000021a (fatal system error).
The session manager initialization system process terminated unexpectedly with a status of 0xc000003a (0x00000000, 0x00000000)

How to fix STOP 0xC000021A error

To determine which process failed, register Dr. Watson as the default system debugger (if it is not already the default debugger). Dr. Watson for Windows NT logs diagnostic information about process failures to a log file (Drwtsn32.log). Also, you can configure this program to produce memory dump files of failed processes that you can analyze in a debugger to determine why a process fails.

To set up Dr. Watson to trap user-mode program errors, follow these steps:

At a command prompt, type System Root\System32\Drwtsn32.exe -I, and then press ENTER.

This command configures Dr. Watson as the default system debugger.
At a command prompt, type System Root\System32\Drwtsn32.exe, and then select the following options:
Append to existing log file
Create crash dump
Visual Notification
After the computer restarts from the STOP 0xC000021A error, run Dr. Watson (Drwtsn32.exe).
View the Dr. Watson log to determine what user mode process may be causing the problem.
If the Dr. Watson log does not contain sufficient information to determine the cause of the problem, analyze the User.dmp file to determine the cause of the STOP 0xC000021A error.

If Dr. Watson did not create a User.dmp file for either Winlogon.exe or Csrss.exe, you may have to use a different tool to generate a memory dump file of the process that fails. Follow the instructions in the Knowledge Base article to troubleshoot a process that shuts down with an exception. While you follow these instructions, monitor the following processes to troubleshoot the STOP 0xC000021A error:
- Winlogon.exe
- Csrss.exe
Note Most STOP 0xC000021A errors occur because Winlogon.exe fails. This typically occurs because of a faulty third-party Graphical Identification and Authentication (GINA) DLL. The GINA is a replaceable DLL component that Winlogon.exe loads. The GINA implements the authentication policy of the interactive logon model. The GINA performs all identification and authentication user interactions.

It is very common for certain types of remote control software to replace the default Windows GINA DLL (Msgina.dll). Therefore, a good first step is to examine the system to see if it has a third-party GINA DLL. To do this, locate the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
Value = GinaDLL REG_SZ

If the Gina DLL value is present and if it is anything other than Msgina.dll, it probably means that a third-party product has changed this value.
If this value is not present, the system uses Msgina.dll as the default GINA DLL.

If this error first occurred after the installation of a new or updated device driver, system service, or third-party program, the new software should be removed or disabled. Contact the manufacturer of the software to see if an update is available.