Thanks to all who answered. On a whim I actually called Microsoft support and got some great help. Turns out that the problem was that somehow the Permissions for two registry keys (one of which I posted) had been somehow totally erased. The representative managed to reset the permissions on the two offending registry keys and voila! all went well. On an even more positive note: I learned a LOT! And, I didn't have to reinstall anything. By the way I had attempted to reinstall by running as administrator, but that didn't work due to the permissions problem.
Kathe