Still getting "This patch package could not be opened" on uninstalling

I tried to uninstall/repair Acrobat Standard 8.0 (with updates .1 thru .4 installed) by clicking on the "Change" (or whatever it is labeled as) button in Add/Remove Programs (on Windows Server 2003) and got the error "This patch package could not be opened". Based on some other posts I found on the internet I installed the Microsoft Installer Cleanup utility and ran it but it did not show any programs listed to select from. I then did a google search for this error and found an article (I think it was on Adobe.com) talking about removing these certain registry keys
For the Retail version of Acrobat 8.x Standard remove:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall\Adobe Acrobat 8 Standard
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall\{AC76BA86-1033-0000-BA7E-000000000003}
HKEY_CLASSES_ROOT\Installer\Features\68AB67CA33010000ABE7000000000030

Even after this, I am still getting the same error message when I click on the setup.exe on the CD. I even tried renaming the Acrobat 8 directory under Program Files before running the Setup.exe but still get the same error. What else can I do short of manually deleting Acrobat 8.0?