Avoid problems when uninstalling IBM WebSphere Portal server

ere are scenarios in which you have to uninstall WebSphere Portal for a particular reason. For example, you might have specified the wrong information in the Setup Manager during installation, or you used Secure way LDAP and now want to install Domino and use Domino LDAP. In these situations, you have to reinstall WebSphere Portal to make these changes, which means you have to first uninstall it. 

Often uninstalling WebSphere Portal becomes a tricky task. The WebSphere environment has several Java processors running in the background, and even if you don't stop one of these Java processors, you can't successfully uninstall WebSphere components. If you have to uninstall WebSphere Portal, you can use the uninstaller that comes with WebSphere Portal, or you can also use the Windows Add/Remove Programs option. 

Make sure you uninstall components in the following order: 

1. WebSphere Portal 
2. WebSphere Application Server 
3. Secure Way LDAP 
4. DB2 
5. IBM HTTP Server 

You can leave the gsktoolkit as it is. Don't mess with this file because it causes problems during your next installation. 

After you remove all these components, reboot your machine. Then remove all physical directories from the machine, such as the C:/IBM/WebSphere directory, which contains WebSphere Application Server and WebSphere Portal information. 

Remove the IBMWPO directory created by the Setup Manager during Portal installation last. You can find this file under the Program files in the IBM directory. Make sure you also check the registry under HKEY_LOCAL_MACHINE/SOFTWARE/IBM to confirm that no previous version information is available. If you follow all these steps, reboot your machine again, and you're ready for a fresh WebSphere Portal installation.

Steps for uninstalling WebSphere Portal Server

While uninstalling the WebSphere Portal Server, all the components that come as a part of the umbrella installation of WPS will also be uninstalled. 

But when the uninstall wizard is run, some folders and registries / registry keys of few components might not have been removed from the file system / registry. This will cause the fresh WPS installation to finish successfully, but with an incomplete installation of the MQ Server (This can be seen in the logs - \log\mq_install.log). 

To ensure a trouble free reinstall, the following steps can be followed.

1. Stop the Portal Server
2. Stop the Application Server
3. Stop all Java processes that are running
4. Uninstall WPS from Add/Remove programs
5. Uninstall MQ components if not used
6. Uninstall WebSphere Embedded messaging
7. Uninstall Secure Way LDAP, if left uninstalled
8. Uninstall DB2 if left uninstalled
9. Do NOT remove “gsktoolkit”
10. Reboot the machine
11. Remove all physical directories from the file system (Do NOT delete “gsk”)
12. Remove IBMWPO directory if it exists
13. Remove the following windows registry entries: *

a. Registry entry for IBM:

· HKEY_LOCAL_MACHINE\SOFTWARE\IBM

b. Two keys for the Embedded Messaging feature for WEMPS:

· HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\Products\1E5744D76F283AA4AAC375A09C50C9A0

· HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\Features\1E5744D76F283AA4AAC375A09C50C9A0

c. Two keys for IBM WebSphere MQ:

· HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\Products\83CD08B8AE134C44AA89E431C1B384F7

· HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\Features\83CD08B8AE134C44AA89E431C1B384F7

Once the above steps have been done, a fresh installation of the WebSphere Portal Server can be started. 

Note: This issue is generic to WAS installations (v5.0 / v5.1) and could possibly be applicable to a wide number of products installed over WAS 5.0 or WAS 5.1.

Precautions: While removing the registry entries, one should be very careful, and before deleting, should always take a backup of the registries to be deleted. For more information on how to take registry backups, please visit the Microsoft website.