A while back, Microsoft was caught distributing updates to computers, without respecting choices made by users or giving the users any choice.
As an aside, I still wonder if this, does not expose a vector, by which even more malicious code could be delivered to a users desktop.
At the time a lot of people said that the updates were benign so it was nothing to worry about. It is now proven that the updates does have serious side effects.
If the update has been installed on your computer, (the only way to check is to find the effected files in the file system and check them manually), and you have to “repair” windows. the stealth updated files will prevent you from being able to run updates on your computer. This might leave your system in an unusable state, but will more likely cut functionality since components will be from different patch levels.