Have you tried an in-place upgrade?
Not all dll's are designed to be registered by regsvr32, so that really isn't a problem.
From looking through your first post, I see that you have tried many things to the point where your PC is likely now in some unknown state where you have multiple issues.
There are a number of sites on the net that describe this process.
https://www.bing.com/search?q=windows%2010%20upgrade%20in%20place
Basically, you install the Media Creation tool, and the run it to download the latest Windows 10 ISO. Then mount the ISO to the problem pc. Run setup.exe from it. Do not boot to the ISO. You have to run setup.exe from the OS that you wish to upgrade.
All of your apps and data file should be retained, but I would recommend backing up any critical data files first as a precaution.