The Update Assistant in Windows 10 cannot be uninstalled, but you can get rid of it
Click your Start Button, type Task Scheduler and hit enter
In the left Pane, navigate to: Windows - Update Orchestrater
Right Pane double click 'Update Assistant'
Click on Triggers Tab
On each of the triggers ( At login . . . etc.) double click and uncheck 'Enabled'
Under 'Update Assistant, there is another event 'Update Assistant CalendarRun'
Do the same for all triggers on that event