Windows Updates are important, but it can be really annoying when it restarts your computer on you.
Don't disable Windows Updates! Just postpone the automatic reboot.
Windows 10 sets up a scheduled task to reboot the system. Disable that task, and Windows won't reboot. Manually disabling it won't work, as the Windows Update service will keep re-enabling it.
The solution I've been using is to have another task that just disables the reboot task.
To make this easy, copy the below text, paste it into a new file, and save it was "Disable Automatic Reboot.xml" (including the quotes, to make sure the file extension is saved).
Then open your Start Menu and Task Manager. Right-click and select "Import Task...", selecting the file you just created.
<?xml version="1.0" encoding="UTF-16"?>
<Task version="1.2" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
<RegistrationInfo>
<Author>XdN</Author>
<Description>Disable Windows Update automatic reboot.</Description>
<URI>\Disable Automatic Reboot</URI>
</RegistrationInfo>
<Triggers>
<CalendarTrigger>
<Repetition>
<Interval>PT1H</Interval>
<StopAtDurationEnd>false</StopAtDurationEnd>
</Repetition>
<StartBoundary>2018-01-01T00:30:00</StartBoundary>
<Enabled>true</Enabled>
<ScheduleByDay>
<DaysInterval>1</DaysInterval>
</ScheduleByDay>
</CalendarTrigger>
</Triggers>
<Principals>
<Principal id="Author">
<UserId>S-1-5-18</UserId>
<RunLevel>HighestAvailable</RunLevel>
</Principal>
</Principals>
<Settings>
<MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
<DisallowStartIfOnBatteries>false</DisallowStartIfOnBatteries>
<StopIfGoingOnBatteries>false</StopIfGoingOnBatteries>
<AllowHardTerminate>true</AllowHardTerminate>
<StartWhenAvailable>true</StartWhenAvailable>
<RunOnlyIfNetworkAvailable>false</RunOnlyIfNetworkAvailable>
<IdleSettings>
<StopOnIdleEnd>false</StopOnIdleEnd>
<RestartOnIdle>false</RestartOnIdle>
</IdleSettings>
<AllowStartOnDemand>true</AllowStartOnDemand>
<Enabled>true</Enabled>
<Hidden>true</Hidden>
<RunOnlyIfIdle>false</RunOnlyIfIdle>
<WakeToRun>false</WakeToRun>
<ExecutionTimeLimit>PT1H</ExecutionTimeLimit>
<Priority>7</Priority>
</Settings>
<Actions Context="Author">
<Exec>
<Command>schtasks</Command>
<Arguments>/change /tn \Microsoft\Windows\UpdateOrchestrator\Reboot /DISABLE</Arguments>
</Exec>
</Actions>
</Task>