Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine the version of the Microsoft Windows® operating system that is running on the Exchange Server computer:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\CurrentVersion

A CurrentVersion value of 4.0 indicates the computer is running Microsoft Windows NT® Server 4.0. A value of 5.0 indicates the computer is running Windows 2000 Server, and a value of 5.2 indicates the computer is running Windows Server™ 2003.

The Exchange Server Analyzer also queries the Active Directory® directory service to determine the value of the serialNumber attribute for all objects with an object class of msExchExchangeServer. If the string value includes Version 5.5, the computer is running Microsoft Exchange Server version 5.5. If the string value includes Version 6.0, the computer is running Exchange 2000 Server. If the string value includes Version 6.5, the computer is running Exchange Server 2003.

If the Exchange Server Analyzer finds the value for CurrentVersion equal to 5.2 and the value for serialNumber contains Version 6.0, an error is displayed. This is not a supported configuration, and you should correct this error as soon as possible.

To correct this error

  1. Do one of the following:

    • Install Exchange 2000 Server on a server that is running a supported operating system, and move the mailboxes to that server.

    • Upgrade Exchange 2000 Server to Exchange Server 2003.

For more information about supported configurations, see the Exchange Server 2003 Deployment Guide (

For more information about Exchange Server and Windows Server 2003, see the Microsoft Knowledge Base article 810591, "Exchange Server Compatibility with Windows Server 2003" (