Topic Last Modified: 2005-11-17

The Microsoft® Exchange Server Analyzer Tool queries the Win32_ComputerSystem Microsoft Windows® Management Instrumentation (WMI) class to determine if the value for the Model key is set to Virtual Machine.

The Exchange Server Analyzer also checks for the presence of the following registry value:

HKEY_LOCAL_MACHINE\Software\Microsoft\Virtual Machine\Guest\Parameters

Additionally, the Exchange Server Analyzer reads the Domain Role key of the Win32_ComputerSystem on the physical computer that is running Microsoft Virtual Server 2005. A value greater than 3 indicates that the physical computer is a domain controller.

If the Exchange Server Analyzer finds that the Model key contains the string Virtual Machine, and that the above registry branch exists, and Domain Role is greater than 3, an error is displayed.

A value of Virtual Machine for the Model key indicates that the Exchange Server computer is running as a guest virtual machine on either Virtual Server 2005 or Microsoft Virtual PC 2004. Because the above registry branch is only created by Virtual Server 2005, its existence means that the Exchange Server computer is running as a guest virtual machine in Virtual Server 2005.

Microsoft does not support running any version of Exchange Server on a virtual machine or on an emulator. This is true for Exchange Server running on Virtual Server 2005, Virtual PC 2004, or any third-party virtual machine program. Exchange Server platforms are designed and tested to run only on physical hardware, particularly those hardware platforms that are listed in the Windows Server Catalog at

Further, running Exchange as a Virtual Server guest on a domain controller is not a best practice in that it does not allow for adequate redundancy across services.

To correct this error

  1. Move the mailboxes from the Exchange server running under Virtual Server 2005 to a non-virtual Exchange Server computer.

  2. Re-home any public folders and transfer any roles held by the virtual Exchange server as necessary.

  3. Uninstall Exchange from the virtual machine to decommission and remove from your Exchange infrastructure and from the Active Directory® directory service.

For more information about moving mailboxes, see the following Microsoft Knowledge Base articles:

For more information about support for Exchange Server computers running in virtual environments, see the Microsoft Knowledge Base article 320220, "Support Boundaries for Exchange Server on a Virtual Machine or an Emulation Machine" (

For more information about Microsoft Virtual Server 2005, visit

For more information about Microsoft Virtual PC 2004, visit