Stop C000021a After Applying Windows NT 4.0 Service Pack

• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server version 4.0

SYMPTOMS

After you apply a service pack for Windows NT 4.0, the computer may stop with the following error message on the subsequent restart:

   Stop:  c000021a {Fatal System Error}
   The session manager initialization system process terminated
   unexpectedly with a status of 0xc0000005 (0x00000000, 0x0000000)

   -or-

CAUSE

This can be caused by a corrupt Windows NT system file, or where one or more Windows NT system files, which are in use, may not be copied properly while applying a service pack.

On Compaq servers that are running Compaq's Insight Manager, the service pack update program would display a message that the file Ntdll.dll was busy. If you skipped the copy of this file and continued the installation, the system will exhibit one of the above symptoms on start up.

RESOLUTION

You resolve this problem by performing one of the following:

• If the system files are on a FAT partition, boot to an MS-DOS bootable floppy disk and replace Ntdll.dll with the updated version from Windows NT 4.0 Service Pack 2.
• Replace Ntdll.dll with the updated version from Service Pack 2 by modifying the Setup.log file on the Emergency Repair Disk (ERD). For more information, please see the following article in the Microsoft Knowledge Base:

        ARTICLE-ID: Q164471
        TITLE     : Replacing System Files Using a Modified Emergency
                    Repair Disk
  
  

• Copy the Setupdd.sys file from Service Pack 2 to the second Windows NT Setup disk, run an Emergency Repair, select the option to "Verify Windows NT System files", and then choose to replace the Ntdll.dll file.
• If the system files are on an NTFS partition, install a parallel copy of Windows NT and replace Ntdll.dll in the original folder with the updated version from Service Pack 2.

1. Change the below services to a startup type of MANUAL using the Windows NT Control Panel Services tool:

         Compaq Automatic Shutdown
         Insight Agents
         SNMP
   

2. Shut down and restart the computer.

3. Install the Windows NT Service Pack.

4. Shut down and restart the computer.

5. Change the services in step 1 back to AUTOMATIC and then start them.

MORE INFORMATION

NOTE: There are other causes for Stop: 0xC000021a as listed below:

For more information, please refer to the following Microsoft Knowledge Base articles:

   ARTICLE-ID: Q156669
   TITLE     : How to Troubleshoot a Stop 0xC000021A

   ARTICLE-ID: Q160658
   TITLE     : Stop C000021A Using MoveFileEx MOVEFILE_DELAY_UNTIL_REBOOT

   ARTICLE-ID: Q139843
   TITLE     : Recovering from STOP 21a Caused by Disk Mirror Sets