Topic Last Modified: 2007-01-05

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine whether the Initial Memory Percentage value has been set:


If the Exchange Server Analyzer finds the value for Initial Memory Percentage present and configured with any value more than 0, a non-default configuration message is displayed.

The Initial Memory Percentage registry setting was introduced as a mechanism for fine tuning the initial amount of memory allocated to the Exchange information store to 10 percent of the total physical memory in the Exchange server. By starting out with this initial allocation and then growing from there, virtual memory fragmentation does not occur as frequently. This registry value should not be set arbitrarily, and should only be used on the advice and direction of Microsoft Product Support Services.

Versions of Exchange Server at Exchange Server 2003 or later include support for special startup switches in Microsoft Windows® 2000 Advanced Server and Windows Server™ 2003 that help reduce virtual memory fragmentation, and additional changes were made to help prevent virtual memory fragmentation in Exchange Server clusters. Therefore, the Initial Memory Percentage registry value is no longer needed on versions of Exchange Server at Exchange Server 2003 or later.

The Initial Memory Percentage registry value works only on computers that are running Exchange 2000 Server. Exchange Server 2003 and Exchange Server 2007 will ignore this value if present, and the value will have no effect. Therefore, you should remove this registry entry before upgrading this Exchange server from Exchange 2000 Server to Exchange Server 2003.

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 remove the Initial Memory Percentage registry setting

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

  2. Navigate to:


  3. In the right pane, delete the Initial Memory Percentage value.

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