I've had the same error for a week now! (Vista 64 SP1)
I tried everything! I've checked dozens of forums, updated to SP2 RC,
used windows readiness tool, windows help etc. but nothing worked! I was
about to give up but then I stumble about this nice free app:
Auto-patcher ( 'AutoPatcher.com ╗ AutoPatcher Vista SP1/Server 2008
32/64 bit' (http://www.autopatcher.com/autopatcher-vista/
I've installed all the missing updates using this program, restarted
Windows and the Windows update is working again!!!
No more this
annoying message about
: *error 80070002!
Before thinking about reinstalling Windows give this program a try!
BTW: There are also versions for XP/2008/Office!