Hang in Winlogon on Workstation Locked Dialog Box

• Microsoft Windows NT Server version 4.0
• Microsoft Windows NT Workstation version 4.0
• Microsoft Win32 Software Development Kit (SDK)
• Microsoft Windows NT Server version 4.0, Terminal Server Edition

SYMPTOMS

A Windows NT computer may appear to stop responding (hang) in the Workstation Locked dialog box, but you will still be able to move the mouse and access the computer from the network.

CAUSE

This problem can occur when running a filter Gina.dll. This problem is caused by a race condition in Winlogon wherein Secure Attention Sequence (SAS) messages are disabled and not reenabled.

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, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

STATUS

Microsoft has confirmed this to be 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.

MORE INFORMATION

A race condition resulting in a computer that quits responding exists in Winlogon if a custom Gina.dll's WlxLoggedOnSas function immediately returns with WLX_SAS_ACTION_LOCK_WKSTA.

Additional query words: SDK

Keywords : NT4SP4Fix kbbug4.00 kbfix4.00.sp4
Version : WinNT:4.0
Platform : winnt
Issue type : kbbug