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Rolling back a failed upgrade

You are in the middle of upgrading from Exchange 5.5 to 2000, and something goes wrong. What do you do? This tip gives some step-by-step advice.

You are upgrading from Exchange 5.5 to 2000 (or maybe 2003). About halfway through the process, something goes horribly wrong.

What do you do?

You may decide that you want to stick with Exchange 5.5 for the time being. Unfortunately, doing so isn't as simple as just restoring a backup because the upgrade process has made significant modifications to the file system, the registry and Active Directory. The only way that you can go back to running a stable Exchange 5.5 installation is to manually undo the changes that the failed upgrade has made, install a copy of Exchange 5.5 and then restore your backup that you made right before the upgrade.

The first part of the process is to manually remove any changes to the system that the upgrade made. In this tip I will show you all of the possible changes that you might have to remove. Just remember that depending on how far into the upgrade you were when the crash occurred, it's very likely that some of the changes that I'm about to show you might not have been made.

Clean the registry—carefully
Begin the process by cleansing the registry. Keep in mind that modifying the registry is dangerous. Making an incorrect modification can destroy Windows and/or your applications. Given that, I recommend that you make another backup before moving forward.

That said, go to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\ and remove the following registry keys if they exist:

Anything starting with LME, MSExchange, or your_server_name-LME

Now, go to HKEY_LOCAL_MACHINE\Software\Microsoft\Exchange and remove the Setup key.

Now that you have cleaned up the registry, check every disk volume on your system for the existence of an EXCHSRVR folder (this folder might be beneath Program Files or another folder). If this folder exists, rename it to something that you can remember.

Now, open the Control Panel and use the Add/Remove Programs icon to remove Internet Information Server (IIS). IIS is located under the Windows Components section of the Add /Remove Programs option. Remember that if you host any other Web sites on the server, then you will need to back those sites up and make note of the related IIS configuration options prior to removing IIS.

After you remove IIS, reboot the server. When the server comes back up you will need to use the Add/Remove Programs option to re-install IIS. Once IIS is back up and running, you will have to re-apply the most recent Windows service pack. You will also have to re-apply any IIS related hot fixes that have become available since the service pack was released.

Re-install with special steps
Now that the remnants of Exchange 2000/2003 are gone, and IIS has been reset, it's time to reinstall Exchange 5.5. However, when installing Exchange 5.5, there are some special steps that you are going to have to do. For starters, when you run the Exchange 5.5 Setup program, you must do so from a command line so that you may specify the /R parameter after the SETUP.EXE command.

While running Setup, it's extremely important that you choose exactly the same setup options as you had originally used with the server. During the Setup process, you must tell Exchange that you want to create a new site (even if your previous site still exists), but you must use the same site name and organization name as you previously used.

When Setup completes, run the Performance Optimizer and place the various databases in the same locations in which they had previously existed. Next, you must install any Exchange 5.5 service packs or hot fixes that were running prior to the upgrade.

It's critically important that the service pack version be the exact same as what was used before. If a newer version is available, do not attempt to install it at this point. When you install the service pack, do so by opening a command prompt and entering the UPDATE.EXE /R command.

The server is now ready for you to restore the Exchange directory service and information stores from backup. After the restoration, reboot the server and start all of the Exchange services. It might be tempting to call it a day, but if you have other Exchange 2000 or 2003 servers in your organization, you will need to do a little more clean-up work to make the Exchange 5.5 server mesh correctly with the rest of your Exchange servers.

Use the Active Directory Connector to force replication on the Configuration Connection Agreement. You will then have to use the Exchange 5.5 Administrator program to change the Alias Name, Admin Display Name, and E-Mail addresses for the site replication service to Directory Service. In the e-mail address portion of the site replication service configuration, you'll have to change SRS to DSA. While you are at it, you should also use the Exchange Administrator program to change the server's Serial Number attribute to reflect the correct version of Exchange.

Next, navigate through the Exchange 5.5 Administrator program and to the server's server level protocols container. Verify that the container contains an LDAP object. If not, then you will have to manually create one. To do so, select the New Other | Raw Object commands from the File menu. Next, double click on Protocol-Cfg-LDAP-Server. You will then be asked which attributes you want to assign to the LDAP object. Assign the following attributes and the corresponding values:

Attribute Value
Admin-Display-Name LDAP (Directory) Settings
Anonymous-Access 1
Association-Lifetime 10
Directory-Name LDAP
Enabled Authorization Packages 0§DPA

Enabled-Protocol-CFG 1
LDAP-Search-Cfg 1
Object-Class 2A864886F71401034D
Outgoing-Msg-Size-Limit 100
Port-Number 389
Use-Site-Values 1

Now, simply restart the Exchange Server's Directory service so that the changes take effect. Finally, use ADSIEDIT to change the server's serial number and version number attributes. Typically, the serial number attribute will look something like: Version 5.5 (Build 2650.24: Service Pack 3). The version number will usually be 2650.

Brien M. Posey, MCSE, is a Microsoft Most Valuable Professional for his work with Windows 2000 Server and IIS. Brien has served as the CIO for a nationwide chain of hospitals and was once in charge of IT security for Fort Knox. As a freelance technical writer he has written for Microsoft, CNET, ZDNet, TechTarget, MSD2D, Relevant Technologies and other technology companies. You can visit Brien's personal Web site at

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