Windows 8 and Windows Server 2012 RTM forced the two OS's to perform Windows Updates the way Microsoft wanted it to work. Windows 8 and Windows Server 2012 were designed to restart less often and be kinder on computer performance by minimizing activity while the computer was active. Forced restarts were also altered so that the end-user had to actually be using the computer to see restart notices, giving them time to save their work before the computer rebooted.
However, for many organizations that have policy and procedures tied directly to patching, this completely disrupted those. This is another area for Windows 8 that many organizations complained about and that Microsoft took heat for releasing a highly consumerized version of an operating system. In essence, they developed Windows 8 to be used in a world void of IT involvement.
Microsoft has now released an update that fixes this IT-reported problem. Per the KB Article:
An update is available that lets you control how the Automatic Updates client applies updates in Windows 8 and Windows Server 2012. After you install this update, the "Configure Automatic Updates" policy setting will work again as it used to in previous Windows operating systems. Instead of installing updates during the daily maintenance cycle, Windows updates will be installed at the time and day that are scheduled in the "Configure automatic updates" policy setting.
Read the full KB Article (2885694) here: Allow configuration of Automatic Updates in Windows 8 and Windows Server 2012
And, once you're done reading that, you can either obtain the update from Windows Update or jump out to the update's (2883201) page: Windows RT, Windows 8, and Windows Server 2012 update rollup: October 2013