VirtualReserveSize is non-default

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool reads the following registry value to determine whether the initial memory allocation for the Exchange Interprocess Communication (ExIPC) component has been changed from the default value:


If the Exchange Server Analyzer finds that the VirtualReserveSize key is present and configured with a value greater than 0, a non-default configuration message is displayed.

ExIPC is a queuing component that permits Inetinfo.exe (Internet Information Services) and Store.exe (Microsoft Exchange Information Store service) to move data back and forth quickly. Generally, the default initial memory allocation for ExIPC is sufficient. By default, the VirtualReserveSize key is not present. It should be added and configured only at the direction of Microsoft Consulting Services or Microsoft Product Support Services.


This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.

To revert to the default configuration

  1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

  2. Navigate to: HKLM\System\CurrentControlSet\Services\EXIPC\Parameters

  3. Delete the VirtualReserveSize key.

  4. Close the registry editor, and restart the Microsoft Exchange Information Store service and the IIS Admin Service for the change to take effect.

Before you edit the registry, and for information about how to edit the registry, see the Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (

For more information about ExIPC, see the following Knowledge Base articles: