http://www.infoworld.com/article/285...b-3004394.html
As I mentioned earlier this morning, Microsoft has pulled the botched patch KB 3004394. That's the Windows Root Cert patch causing endless problems -- Windows Defender wouldn't start, installing KB 3004394 blocked installing other Windows Updates, UAC prompts appeared in the weirdest places, MSE wouldn't install, VirtualBox stopped working, and on and on.
http://www.infoworld.com/article/285...b-3004394.html
KB 3024777, specifically designed to take out this week's Black Tuesday fiasco, KB 3004394, on Windows 7 SP1 and Windows Server 2008 R2 SP1 machines.
TLDNR; uninstall KB3004394, install KB3024777