I had the same issue on my laptop. I tried every built-in reset (including the one which wipes all files), as well as the in-place upgrade, and could not fix the issue. I ended up going with a clean install there.
I didn't think what I was doing was a major change. The only thing I did to apps which I still wanted to use was take ownership and give my user account full control privileges, but this was enough to cause them to no longer function.