🚀 go-pugleaf

Sandy, I'm glad I could be of help. I've sent my comments and the link to this discussion to Adobe so they're free to clarify things for us.

The most interesting question is, of course, why only some but not all PCs experience this problem. For comparison, I looked at the registry from a "normal" machine. The keys that were unwritable on a "problem" machine have a different owner there. Interestingly, it's not Administrators group. It is a MS domain account with administrator rights, specifically the user who configured this machine. It's also most probably the user who installed the previous version of Adobe Reader (7.0.x) there.

In contrast, the keys from the "problem" machine were originally (before the fix) owned by local Administrator account (i.e. the built-in Windows account). Also, their permissions did NOT include Administrators group. (That's why it was impossible to change them until changing the owner.)

Here, I guess, we are approaching the important point. It looks like these two problem keys existed before the installation of Reader 8. It looks like they were created with wrong permissions. Still, in some cases all worked well while in other cases it didn't. Were these keys created during the installation of one of the previous Reader versions? Quite probably yes.

Now suppose that the PREVIOUS installation was done by a member of domain admins. As a result, the keys are owned by this member and later an SMS account or another member of Domain Admins attempts to install Adobe Reader - and all works well. Now another case: the previous installation was done by the built-in Windows account, local Administrator. Then SMS or a member of Domain Admins attempts to install the new version of Adobe Reader - and fails because the permissions on the keys only allow the local Administrator to do the install.

Unfortunately, I don't have time to fully reproduce these two scenarios from scratch, so all the above is kind of guessing. Still, I hope this may give some clues to those who wish to track the problem back to the Adobe reader installation procedure (which creats the keys). From the Adobe TechNote 329137, it looks like the error was introduced in a previous version and is most probably still there.