Microsoft is now actively pushing the Windows 10 October update
Microsoft may install Windows 10 1809 on your PC, whether you particularly want it to or not. According to new reports, it is doing so via the automatic detection of Windows 10 Update Assistant on devices running versions 1507 to 1709. This may be less than good news for people still worried about the October update's many bugs, or what the size of the update file may do to their data plans.
On the other hand, there are many workarounds available to users who want to postpone their Windows updates for now. For example, they could pause Windows updates - or leave them paused in the event that this setting is on already. This option is found under Advanced options on the Update & Security page in Settings. Alternatively, a user could set their WiFi network to metered (under Settings>Network & internet>WiFi>Manage network).
However, the most effective way to prevent Windows from updating is probably to uninstall the Update Assistant. This may be done via the Control Panel or Start menu. Alternatively, the user could simply delete the folders found at [applicable drive letter]:\Windows\Updateassistant and :\Windows10upgrade.