I'm a year behind in installing MS security updates etc. When I attempt to install them, they fail consistently. I have followed many different instructions found in forums such as this, and have tried the MS Fix-It tool. Nothing has woked.
Go to Start and Run, type in "services.msc" and check that AutoUpdate is set to Automatic and Started, then Windows Installer must be on Manual not Disabled. No other system tweaks that may block automatic updates or firewalls/AVs that may do the same.