How to re-enable the RPCSS caching of COM class information in Windows Server 2003 SP1, in Windows XP SP2, and in Windows 2000 Post-Service Pack 4 (911650)


The information in this article applies to:

  • Microsoft COM
  • Microsoft Windows Server 2003 SP1
  • Microsoft Windows XP Service Pack 2
  • Microsoft Windows 2000 Server SP4
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

INTRODUCTION

This article describes how to re-enable the RPCSS caching of Microsoft Component Object Model (COM) class information in Microsoft Windows Server 2003 Service Pack 1 (SP1), in Microsoft Windows XP Service Pack 2 (SP2), and in Microsoft Windows 2000 Post-Service Pack 4.

Starting with Windows Server 2003 SP1, Windows XP SP2, and Windows 2000 Post-Service Pack 4, RPCSS no longer caches certain COM class information from the registry by default. This change was made to make sure that registry key handles are closed as soon as possible to prevent possible data loss.

MORE INFORMATION

In some applications that have COM caching disabled, you may experience a small increase in CPU utilization in the RPCSS instance of the Svchost.exe process. This problem occurs because the RPCSS instance must read these registry values every time that the values are needed.

A registry setting is available to re-enable the caching of the COM class information. However, re-enabling the caching of the COM class information may cause the data loss that is mentioned in the summary section.

The EnableCatalogCachingForBaseCOM registry value is included in Windows Server 2003 SP1 and in Windows XP SP2. You can use this registry value to re-enable the caching of the COM class information.

In Windows 2000, the caching of the COM class information is disabled after you apply the MS04-012 security update. However, the MS04-012 security update provides support for the EnableCatalogCachingForBaseCOM registry value. You can use this registry value to re-enable the caching of the COM class information. For more information about the MS04-012 security update, click the following article number to view the article in the Microsoft Knowledge Base:

828741 MS04-012: Cumulative Update for Microsoft RPC/DCOM

To enable the caching of the COM class information, follow these steps:

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.
  1. Click Start, click Run, type regedit, and then click OK.
  2. Locate and then click the following subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole\

  3. If an EnableCatalogCachingForBaseCOM registry value exists, go to step 6.
  4. On the Edit menu, point to New, and then click DWORD Value.
  5. Type EnableCatalogCachingForBaseCOM, and then press ENTER.
  6. Right-click EnableCatalogCachingForBaseCOM, and then click Modify.
  7. In the Edit DWORD Value dialog box, type 1 to enable caching of the COM class information, and then click OK.

    Note A value of 0 disables caching of the COM class information.
  8. On the File menu, click Exit.
This issue resembles the issue that is described in Microsoft Knowledge Base article 911193. However, that issue differs from this issue. For more information Microsoft Knowledge Base article 911193, click the following article number to view the article in the Microsoft Knowledge Base:

911193 FIX: COM+ applications may consume more CPU resources after you apply the MS04-012 security update to a computer that is running Windows 2000 Server or Windows 2000 Professional

REFERENCES

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

256986 Description of the Microsoft Windows registry

Modification Type:MajorLast Reviewed:10/3/2006
Keywords:kbhowto kbinfo kbComponentDevelopment kbDCOM kbASP kbPerformance kbDevelopment KB911650 kbAudDeveloper kbAudITPRO
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