OK just did a test with a user who had the same problem.
In the v2.8.1 I had the reset registry permissions no longer change the owner. Since Windows 8 was so picky on it I wanted to see how the others did. Well on my test systems they where fine since all the permissions where normal.
For the user I helped he had cleaned up a lot of viruses from the system and after running the repairs got the same errors as you. This is because the viruses had changed the owner on some registry keys and so when the program tried to register the dll files on the system they didnt have permissions and failed. And so you would get class not registered.
So I made a new build and had the reset registry permissions take ownership again like it always use to and that did the trick, mmc was fixed and the other errors all got fixed as well.
So I am making v2.8.2 and putting it out asap
Shane