Today, the Microsoft Security Response Center (MSRC) posted details about the December security updates.
If you have automatic updating turned on, most of these updates will download and install on their own. Sometimes you may need to provide input for Windows Update during an installation. In this case, you’ll see an alert in the notification area at the far right of the taskbar—be sure to click it.
In Windows 8, Windows will turn on automatic updating during setup unless you choose to turn it off. To check this setting and turn on automatic updating, open the Search charm, enter Turn automatic updating on or off, and tap or click Settings to find it.
For other versions of Windows, you can check whether automatic updating is turned on through the Microsoft Update website. This will open Windows Update in Control Panel; if automatic updating is not turned on, you’ll be guided through the steps to set it up. After that, all the latest security and performance improvements will be installed on your PC quickly and reliably.
If you are a technical professional
The Microsoft Security Bulletin Advance Notification Service offers details about security updates approximately three business days before they are released. We do this to enable customers (especially IT professionals) to plan for effective deployment of security updates.