I'm becoming desperate with this issue, that's keeping me busy for some weeks now.
I got an SBS2011 (without Exchange, only DC) which has not updated since 2014 due to error 800706F7. Any other update fails due to this error.
What I tried so far:
-Update pack KB3004394 is not installed (at least wusa /uninstall /kb:3004394 reports it).
-cannot even install update pack KB3024777 (it simply happens nothing when I run the exe-file)
-AVG Antivir was deinstalled
-I run System Update Readiness Tool KB947821