Our most common problem with Windows Updates is the ""cannot process the lockfile"" error... with the user permissions to this key (attached) being reset.
Emailing instructions on how to fix is easy enough, but yesterday we ran into a user where HKCC was entirely blank for a user, even when starting regedit as admin, so right-clicking on software and giving Users full control was not possible.
There has to be a way Sage can store this information in some other location, so WU's don't cause this problem.