Try to install Adobe Reader with a New User Account (Admin Rights)
Which OS do you have and which language in Adobe Reader you are trying to install
in the previous post I leave out that everything starts with the automatic update.
The update of Adobe Acrobat didn't finalize and leave me a message like before I reported. Then I tried to uninstall AR 9 and the process still finalized with error but now, maybe I could solve the problem...I uninstall the program with Revo uninstaller and download the new release of Adobe Reader 10, that maybe do not use the registry key corrupted like the update of AR 9 did.
So, I still have the problem in the registry probably but I could install Adobe Reader.
I think I can leave the key in the registry without any problem, I hope it doesn't affect any program or application.
Thank you anyway
Great good to know Adobe Reader 10 is installed finally
Maybe a registry file which got corrupted not letting you installed Adobe Reader 9