Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool queries the Win32_ComputerSystem Windows® Management Instrumentation (WMI) class to determine which options are set in the SystemStartupOptions property. The Exchange Server Analyzer also queries the Active Directory® directory service to determine the count for the homeMDBBL attribute of the mailbox store object (msExchPrivateMDB). The resulting count is the number of mailboxes found on the Exchange Server computer.

If the Exchange Server Analyzer finds that the /PAE startup switch has been set in the boot.ini file on an Exchange server that has fewer than 500 mailboxes, and is running on a Windows 2000 Server, a warning is displayed.

Physical Addressing Extensions (PAE) enable a computer to access more than 4 GB of physical memory (RAM). Exchange Server does not support PAE. PAE enables Windows to access more than 4 gigabytes (GB) of physical memory. Exchange Server cannot use more than 4 GB of physical memory, and there is no benefit to installing more than 4 GB of RAM on a computer that is dedicated to running Exchange Server. PAE is enabled when the /PAE startup switch is present in the Boot.ini file.

To correct this warning for Windows 2000 only, it is recommended that you remove the /PAE switch from the Boot.ini file.

To correct this warning

  1. In Windows Explorer, navigate to the System partition. This is the partition that holds the hardware specific files such as Boot.ini and NTLDR.

  2. If you cannot see the Boot.ini file, it could be because the Folder Options are set to Hide protected operating system files. If this is the case, in the Explorer window, click Tools, click Folder Options, and then click View. Click Show hidden files and folders. Clear the Hide protected operating system files (Recommended) check box. When prompted, click Yes.

  3. When the Boot.ini file is visible in Windows Explorer, right-click the file, click Open With, and then click Notepad to open the file.

  4. In the [Operating Systems] section, remove the /PAE switch.

  5. Save and close the file, and restart the Exchange Server computer for the change to take effect.

For more information about the /PAE switch in Boot.ini, see the following Microsoft Knowledge Base articles: