Adobe Standard 8.0.0 - applying patch 8.1

Adobe's knowledge base provides, maybe, some insight into this: http://kb.adobe.com/selfservice/viewContent.do?externalId=330497&sliceId=1It is for A6 & A7, however, much of the inistaller logic for A8 is the same and so may apply.In genera, info on the error: 1635 - ERROR_PATCH_PACKAGE_OPEN_FAILED
This patch package could not be opened. Verify that the patch package exists and is accessible, or contact the application vendor to verify that this is a valid Windows Installer patch package.

What may be happening is that when you pass the command to MSIEXEC via SMS MSIEXEC cannot access (a.k.a. find) the .MSP.

Not a lot to go on, but hopefully something will help.

Note: to get this I did a Google on 'msi error 1635'

When one gets the message "This patch package could not be opened. Verify that the patch package exists and is accessible, or contact the application vendor to verify that this is a valid Windows Installer patch package." when trying to install an update to the program it may mean that the Registry for the program in question is corrupted. Microsoft has a Utility to fix the problem. It is called "Windows Installer Cleanup Utility" that will clean out the Registry Files for the program. You must reinstall the program to reinitialize the Registry Entries. Updates should then work. I had to do this for Adobe Acrobat 8.0 Standard and Microsoft Office XP after installing a new Hard Drive and moving the system from the old Hard Drive.