On my Windows 7 x64 system, the updates seemed to work fine with avast!, but not with Windows itself.
KB3004394 made a mess of core Windows functions. UAC got borked so that .exe files in the Windows and System directories wouldn't run without requiring UAC confirmations (sometimes more than once), everything else ran slower than usual, boot time was much longer, etc. Microsoft has apparently since pulled this one, which other forums have identified as an update for Root Certificate Manager, from Windows Update.
After uninstalling 3004394 but keeping the others that came through yesterday, everything works fine again. So, it seems you can install everything except this one, and should have no problems.
Crashman