Microsoft KB Archive/810088

= CPU Usage May Be High After You Turn On Auditing for HKEY_LOCAL_MACHINE\System =

Article ID: 810088

Article Last Modified on 10/26/2006

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APPLIES TO


 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Service Pack 3
 * Microsoft Windows 2000 Service Pack 3

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Important This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit 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 try to audit the success or failure access of the Enumerate Subkeys on the following registry key, CPU usage may increase:

If you turn off security auditing on this registry key, the CPU usage does not increase.

On a single-CPU computer, CPU usage may become 100 percent. If you open Windows Task Manager, you see that the following processes are using CPU time:
 * Services.exe (from 60 to 85 percent)
 * Lsass.exe (from 15 to 25 percent)
 * System (from 5 to 15 percent)

You will also see a large number of Success Audit events (events 560 and 562) in the security event log.



Service Pack Information
To resolve this problem, obtain the latest service pack for Microsoft Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

Hotfix Information
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows 2000 service pack that contains this hotfix.

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 about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix has the file attributes (or later) 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 tool in Control Panel.   Date         Time   Version        Size    File name ---  12-Nov-2002  19:04  5.0.2195.6125  45,328  Eventlog.dll

After the fix is applied, the GetComputerName function is called only one time. It caches the result (the length of the computer name).



MORE INFORMATION
To configure the audit policies, edit the following Group Policy settings:
 * Windows Settings
 * Security Settings
 * Local Policies
 * Audit Policy

To verify whether auditing has been activated on the registry key, follow these steps.

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.  Click Start, and then click Run. Type regedt32.exe, and then click OK to start Registry Editor. Locate and then click the following registry subkey:

 On the Security menu, click Permissions. Click the Advanced button. Click the Auditing tab.</li> Click to select Everyone, and then click the View/Edit button.

The Auditing Entry for ActiveComputerName dialog box appears. This window lists Success and Failed options for the following access events: <ul> Query Value</li> Set Value</li> Create Subkey</li> Enumerate Subkeys</li> Notify</li> Create Link</li> Delete</li> Write DAC</li> Write Owner</li> Read Control</li></ul> </li></ol>

To stop auditing the Enumerate Subkeys action for this registry value: <ol> Click Start, and then click Run.</li> Type regedt32.exe, and then click OK to start Registry Editor.</li> Locate and then click the following registry subkey:

</li> On the Security menu, click Permissions.</li> <li>Click the Advanced button.</li> <li>Click the Auditing tab.</li> <li>Select the group or groups that are auditing the Enumerate Subkeys value for ActiveComputerName, and then click Remove.</li> <li>Click OK to quit Registry Editor.</li></ol>

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STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Microsoft Windows 2000 Service Pack 4.

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