Stop 0xC000021A When Starting Task Manager with CTRL+ALT+DEL

This article was previously published under Q183840
This article has been archived. It is offered "as is" and will no longer be updated.
SYMPTOMS
The Task Manager can be started by pressing CTRL+ALT+DEL and then clickingTask Manager on the Security dialog box. However, if there are many userenvironment variables defined, running Task Manager from the Securitydialog box may cause a STOP C000021A exception error message.
CAUSE
The System Environment Block becomes corrupted by the Winlogon service ifthe size of the User Environment is significantly large. This can also becaused by the installation of many applications on a system.
RESOLUTION
To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in theMicrosoft Knowledge Base:
152734 How to Obtain the Latest Windows NT 4.0 Service Pack

STATUS
Microsoft has confirmed that this is a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.
environment winlogon crash hang
Properties

Article ID: 183840 - Last Review: 10/07/2013 22:46:11 - Revision: 2.2

  • Microsoft Windows NT Server 4.0, Terminal Server Edition
  • Microsoft Windows NT Server 4.0 Standard Edition
  • Microsoft Windows NT Workstation 4.0 Developer Edition
  • kbnosurvey kbarchive kbhotfixserver kbqfe kbbug kbfix kbqfe KB183840
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