Update Acrobat 8.1.1 to 8.1.2

I did update for all my Mac, Win; English, Chinese versions, with manual & automatic. All of them were done smoothly.Acrobat installer asks you whether you want to cache the installation source onto the computer when first time the Acrobat installed onto the computer. I guess that you didn't pick that option for the initial installation and that's why the 8.1.2 updater couldn't find the installation source.

I did not cache the 528MB installation file on my hard drive. I saved it to a CD.

I copied the 20MB update to the same CD and ran the update from the CD. However the install failed and I got the same error message.

How can I tell the install where to find the source file? Would simply copying the file to my hard drive work? What directory should I copy it to?

Thanks for your insight.

The cached installation files are locate:
[drive]:\Program Files\Adobe\Acrobat 8.0\Setup Files\

I believe that it is not necessary to copy the files onto the harddisk. Instead, you may insert the original installation CD when you perform the update. The updater will search for the source files from the CD directly.

Good Luck!

I don't think I was clear in my earlier messages, I apologize.
Please note; I don't have an installation CD.
I downloaded the program from the Adobe website.
All I have is an unexpanded 528MB installer exe file.
I did not cache the install files.
I saved the 528MB file to a CD and then removed the original file from my hard drive.

I tried the update again this time with the CD in the disk drive.
As you would expect the installation failed.
Error Message: "Installation Source is not available. Verify that the source exists and you can access it."

I'm hoping I won't have to uninstall, fiddle with the registry, and then reinstall the program, this time caching the install files. All of that just so I could run the 8.1.2 update.

Any other suggestions?
Thank you for your persistence and insights.

Uninstall yes, fiddle with regedit hopefully not. try following the instructions for this Acrobat 7 kb:

http://www.adobe.com/cfusion/knowledgebase/index.cfm?id=332773