The video link I posted would have showed you how to restore the registry when windows wont boot, you can do it from the cmd window in the repair windows section that boots up.
But I am glad you got i back up and running. The only difference in the beta repair is that it sets the permissions on the system volume information folder, ran it on tons of machines and never had the problem you did, which makes me think there is something else going on and because of that there was a side effect of the error you got after running the beat repair.
I just answered so many forum posts so I cant remember if I asked this yet, but did you check the drive for bad sectors yet?
shane