Users
destroy Computers and OS
They do things they shouldn't: Visit questionable locations or networks, open any file or mail without careful consideration and protections
They fail to do things they should: Critical Updates, current A/V tools and Backups, Preventative Maintenance (housekeeping) , use a UPS or surge protection depending on regional power history needs
Prevent Physical Damage: Don't place where it can be sat upon, knocked off the desk easily or trip on its cables... Preventative Maintenance (lint and dirt cleaning)
I ran
the same install of XP every day for 10 years until I accidentally dropped a file shortcut onto 'Start" instead of the Programs Menu

because it destroyed the ability to launch any Windows GUI type Programs.
I applied service packs, Critical Updates in a timely manner AFTER reviewing the proposed list (I have seen bad/wrong hardware drivers on the list).
Automatic is for
Notifications
Manual is for the choosing of actual application of those files