Priority #9 - Keeping your system up to date with the latest security updates
Security holes are cropping up all of the time - in both applications and in operating systems (such as Microsoft Windows and Apple OS X). The vendors do get around to fixing these issues, but we need to be sure that we are going to get those fixes automatically when they become available.
Apple OS X
OS X automatically checks for system and security updates, unless you’ve switched this feature off. Check the settings in System Preferences, App Store. To keep up to date with the latest security fixes, check ‘Automatically check for updates’ and all of the sub-options beneath it.
As with Apple OS X, Windows has the ability to check for and implement security updates automatically.
Check out Windows Update: FAQ for instructions for your versions of Windows.