Computer Stops Responding to Mouse or Keyboard Input

ID: Q247886

The information in this article applies to:

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

SYMPTOMS

While you are using your Windows NT 4.0-based computer, it may stop responding to mouse or keyboard input. If you use the Task Manager tool to view the current processes that are running on your computer, you may observe that the Central Processing Unit (CPU) usage is at or near 100 percent. Also, the "% Processor Time" and "Priority Current" counters in the Performance Monitor tool Thread object may indicate that a thread has a higher priority (and is subsequently using more CPU time) than was expected.

CAUSE

This problem can occur when the NtSetInformationThread() function does not check threads properly before granting them a priority. This allows a thread to acquire HIGH_PRIORITY (or level above LOW_REALTIME_PRIORITY) and access to privileged mode with unlimited access to the CPU.

RESOLUTION

A supported fix that corrects this problem is now available from Microsoft, but it has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next Windows NT 4.0 service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://www.microsoft.com/support/supportnet/overview/overview.asp

The English version of this fix should have the following file attributes or later:


   Date         Time     Size        File name      Platform
   -------------------------------------------------------------
   10/25/1999   04:54p     952,192   Ntkrnlmp.exe     x86
   10/25/1999   04:53p     932,032   Ntoskrnl.exe     x86
   10/25/1999   04:52p   1,405,184   Ntkrnlmp.exe   Alpha
   10/25/1999   04:51p   1,376,896   Ntoskrnl.exe   Alpha

STATUS

Microsoft has confirmed this to be a problem in Windows NT 4.0.

Additional query words:

Keywords : ntsp kbbug4.00 kbfix4.00
Version : winnt:4.0
Platform : winnt
Issue type : kbprb