To manage your computer security.

To manage your computer security.
Change your Important updates become "Download updates but let me choose whether to install them".
This allow you to manage your computer security and let you decide when is the best time to restart your computer. For example, Only decide to restart your computer, when you finished saved an important note take you are working on.
If you are not change this Important updates default option, the Important updates restart your computer immediately upon updates finish downloaded from internet and ignore your important notes that still open or unsaved.