Office 16 Click-to-Run Extensibility Component could not modify 137 protected registry keys during installation or update of Office 365

Palcouk - A few more things in response to your helpful post above:

The only "MS kb on uninstalling Office" I have found is https://support.office.com/en-us/article/uninstall-office-from-a-pc-9dd49b83-264a-477a-8fcc-2fdf5dbf61d8 , which in turn provides the same "deep" uninstall file I mentioned, o15-ctrremove.diagcab.

In that article, there is no mention of "click once trust prompt".

Finally, I read your article about the "click once trust prompt" and looked for the registry key, and that sub-key does not exist.  There is no "Trust Manager" under "Security".

However, before I try to do anything about that, why would I want to?  In all the efforts I've made to fix this problem, whenever I've been prompted to go forward, I hit "yes".

Thanks.  I'm still hoping that my other steps above will work out, starting with using your first link for the "MS Utility against Office".

Palcouk - UPDATE - NO LUCK - The same seven keys would not accept three modifications each.

Any ideas?

Added note on odd aspects of seven registry keys that are “protected” and throw Warnings when I update Office 365 Home

One of the seven is:

Software\Classes\CLSID{3050F667-98B5-11CF-BB82-00AA00BDCE0B}\InprocServer32

Its “Advanced Security Settings” show the following (and this is after I gave Full Control to Everyone, Account Unknown and Users and made sure others had Full Control) – two screenshots:

and

NOTE HOW there are four DUPLICATE listings for SYSTEM, Administrators, Users and Account Unknown that say “Read”.  Two things:

1. I cannot Edit those “Reads”.  Any attempt to double-click on any of those last four does not work – I just bounce back into the upper list that already says “Full Control”. (All other attempts to check the Permissions of the upper part of the list indicate Full Control.)
2. I cannot check “Replace all child object permissions with inheritable permissions from this object”.  If I do and hit Apply, it unchecks itself.

I see these symptoms on at least four of the seven "protected" keys and a few of these symptoms on the other three.

So, might this be connected to the reason I get warnings that these keys are protected and cannot be modified each time I update O365?

glnzglnz <br/> ► In the office, Dell Optiplex 7010 with 4GB RAM, Win 7 Pro 32-bit and Office 2010. <br/> ► At home, Dell Optiplex 7010 with 16GB RAM dual-booting Win 7 Pro 64-bit (now with Office 365 Home) and Win 10 Pro 64-bit. <br/> ► Also still have Dell Optiplex 755 with 4GB RAM with Win XP Pro SP3 (which still gets updates with the POS hack) and Office 2003.

Also, is it relevant that all seven stubborn registry keys end with "InprocServer32"?

When I started this philosophical-life struggle two years ago, an MS telephone tech person wrongly had me install the 32-bit version of O365 when I had always wanted the 64-bit version.  We UNinstalled the 32-bit and re-installed the 64-bit.

So, is "InprocServer32" a holdover from the initial installation that should no longer be there?  (And keep in mind I have tried to do some VERY thorough UNinstalls and re-installs since then.)