Microsoft KB Archive/925104

= The System log reports many &quot;PerfOS event ID: 2001&quot; errors when you use a Microsoft Windows Server 2003-based computer that has more than 32 processors =

Article ID: 925104

Article Last Modified on 3/28/2007

-

APPLIES TO


 * Microsoft Windows Server 2003, 64-Bit Datacenter Edition
 * Microsoft Windows Server 2003, Enterprise x64 Edition
 * Microsoft Windows Server 2003, Datacenter Edition (32-bit x86)
 * Microsoft Windows Server 2003, Enterprise Edition (32-bit x86)
 * Microsoft Windows Server 2003, Datacenter Edition for Itanium-Based Systems
 * Microsoft Windows Server 2003, Datacenter x64 Edition
 * Microsoft Windows Server 2003, Enterprise Edition for Itanium-based Systems
 * Microsoft Windows Server 2003, Enterprise x64 Edition

-



Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry



SYMPTOMS
When you use a Microsoft Windows Server 2003-based computer that has more than 32 processors, you may notice that many events are reported in the System log that resemble the following:

Event logged:

=
==

PerfOS event ID: 2001 - &quot;Unable to get interrupt information from system.&quot;



CAUSE
This problem occurs because one or more 32-bit applications have used the NtQuerySystemInformation function in order to determine the number of processors that are available for the computer. If more than 32 processors are available, the PerfOS event is logged every time that the NtQuerySystemInformation function is used.



Windows Server 2003-based computers that are running Service Pack 2 (SP2)
Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

This problem was addressed in Windows Server 2003 Service Pack 2 (SP2). You do not have to download a hotfix to resolve this problem. However, some Windows registry information is missing. To resolve this problem, you must modify the Windows registry. To do this, follow these steps:  Click Start, click Run, type regedit, and then click OK. Locate and then click the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\PerfOS\Performance

 In the Edit menu, point to New, click DWORD Value, type LogErrorToFile, and then press ENTER. Double-click LogErrorToFile, type 0, and then click OK.

Note When you set the LogErrorToFile value to 0, PerfOS events are no longer logged in the System log. You can enable logging again by setting this value to 1.





Service pack information
To resolve this problem, obtain the latest service pack for Windows Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

889100 How to obtain the latest service pack for Windows Server 2003

Windows Server 2003-based computers that are running Service Pack 1 (SP1) or earlier versions
When you install this hotfix on computers that are running Service Pack 1 (SP1) or earlier versions, you do not have to modify the registry to resolve this problem.

Prerequisites
There are no prerequisites for installing this hotfix.

Restart requirement
You must restart your computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows Server 2003, Itanium-based computers that are running SP1 or earlier versions

Windows Server 2003, x64-based computers that are running SP1 or earlier versions

Windows Server 2003, x86-based computers that are running SP1 or earlier versions



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section. This problem was first corrected in Windows Server 2003 Service Pack 2.

<div class="moreinformation_section">

MORE INFORMATION
For more information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Keywords: kbwinserv2003sp2fix kbexpertiseinter kbexpertiseadvanced kbwinserv2003presp2fix kbprb kbfix kbhotfixserver kbqfe kbpubtypekc KB925104

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.