Store RPC prorate registry parameters are not set to their correct values

[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 three registry keys to determine whether their values have been modified from their default values. All three keys are DWORD values that can be found at:

HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\Image File Execution Options\STORE.EXE\RpcThreadPoolThrottle

The keys have the following names and default values:


DWORD value Default Decimal Value
  • ProrateStart

  • 40

  • ProrateMax

  • 10,000

  • ProrateFactor

  • 100

If the Exchange Server Analyzer finds that any of the above default values have been changed, a non-default configuration message is displayed.

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.

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

  2. Navigate to: HKLM\Software\Microsoft\WindowsNT\CurrentVersion\Image File Execution Options\STORE.EXE\RpcThreadPoolThrottle

  3. In the right pane, double-click the entry whose value has been changed, and configure it for its default value.

  4. Repeat step 3 if more than one value was changed.

  5. Close the registry editor and restart the Microsoft Exchange Information Store 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 store process threads, see the Knowledge Base article 267255, "Store.exe Threads Use Up Available Memory" (


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