Well, it happened again. Woke up this morning, turned on my computer, practically a factory resetting, had to open System Restore and revert back to the same restore point for the third time.
So apparently, when you turn off Windows Updates, it doesn't apply to updates made to Windows itself (as in the OS, not your system) . . . so I guess there's no escaping this . . . I guess I'll just have make sure everything is properly backed up and then just reimport everything and redo all of my personal settings next time this happens, because it looks like there's no getting around this.