Microsoft announced that Windows 8.1 user devices without the Windows 8.1 update will no longer receive security patches.
In the old days, “Windows 8.1 update” would be referred as a “service pack”, however Microsoft decided to call it the former.
Unfortunately, there are reports that users have issues installing the new Windows 8.1 update and you have to install it if you wish to receive future security patches.
Not much of a choice really…