We ran into a problem with a PC that had the Microsoft Firewall Client 2000 from ISA (Internet Security and Accelerator) on it. We recently upgraded our ISA server to the 2004 version. You can run the older client on the newer version but it doesn’t encrypt the traffic and it allows traffic that is normally blocked on a user level to work. So, we disabled the ability for the old client to work and began removing it from all of our computers and then installing the new version.
On one PC the old version wouldn’t un-install correctly and the new version won’t install if it’s not removed. You will get an error message that says something like “Microsoft Firewall Client 2004 cannot be installed over a previous version. Please remove the older version and try again.” Well, since the uninstall failed and it removed the old version from the Add/Remove programs we were stuck. After some poking around in the internet I found instructions on Microsoft’s site for removing the client from a Windows 98 computer. The computer I was working on is actually Windows XP, but the instructions worked on it as well. Here are the registry keys that need to be removed, so that the new version won’t think the old version is still installed:
Remove 8A95A7C8EBA9A954A939802C184A2A46
from HKEY_CLASSES_ROOT\Installer\Features\
Remove 8A95A7C8EBA9A954A939802C184A2A46
from HKEY_CLASSES_ROOT\Installer\Products\
Remove Firewall Client
from HKEY_Current_USER\Software\Microsoft\
Remove Firewall Client
from HKEY_LOCAL_MACHINE\Software\Microsoft\
Remove Firewall Client
from HKEY_USERS\Software\Microsoft\
Remove 8A95A7C8EBA9A954A939802C184A2A46
from HKEY_LOCAL_MACHINE\Software\CLASSES\Installer\Features\
Remove 8A95A7C8EBA9A954A939802C184A2A46
from HKEY_LOCAL_MACHINE\Software\CLASSES\Installer\Products\
Remove 945E895D0A5100149B4B8D6E01A3DA26
from HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Installer\Components\
Remove 8A95A7C8EBA9A954A939802C184A2A46
from HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Installer\Features\
Remove the C”\Program Files\Microsoft Firewall Client
from HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Installer\Folders\
Remove the {8C7A59A8-9ABE-459A-9A93-08C281A4A264}
from HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
The instructions also said to find the Wspcpl32.cpl file in %Windir%\System. Delete this file to remove the Firewall Client icon in Control Panel. I didn’t need to do this step, I guess the uninstall did this before failing. I did find the install directory C:\Program Files\Microsoft Firewall Client and deleted it. After these steps the Firewall Client 2004 installed without a problem.