I had a similar or same problem. I uninstalled Avast, installed all the updates and reinstalled Avast. Check your third party security software.
In case you've tried a refresh (and it didn't work), let me tell you, installing from ISO is a breeze. Time consuming but smooth and clean. Give it a try if you've run out of ideas. PS: Love that avatar you've put there.
That seemed to have done the trick! After uninstalling avast and restarting. I tired up Windows update and it installed all updates including that huge GA one! So thanks man Thanks!