This questions has been answered previously, e.g. here, but all the answers I've seen require using a dropdown in Settings> Update & Security> Advanced Options.
On my version of Windows 10 Pro, there is no such dropdown:
How can I prevent automatic restarts?
Setting the "No auto-restart with logged on users for scheduled automatic updates installations" GPO didn't work for me. I woke up this morning and my machine had been rebooted. (I was using the computer last night and didn't even get a warning.)
This suggestion from techjourney.net looks more promising.
Windows will attempt to re-enable the task automatically, so you also need to modify permissions on the task file.
Take ownership of the file by clicking the "Change" link next to the owner and typing in your name. Disable inheritance via the button at the bottom.
Change all permissions to read or read & execute only.
All the suggested hacks workarounds seems not to work with the anniversary update. But there is still an option: You can periodically update the "active hours" in the settings. However, this is no fun to do manually, but there is a small windows service that can do it for you: https://www.udse.de/en/windows-10-reboot-blocker
Edit:
Microsoft are going to release a way to snooze updates. The Verge - Microsoft is making it easy to stop Windows 10 rebooting your PC randomly for updates
I'm not sure if the settings app allows you to do this anymore. I have had a look but I cannot find anything. This solution below will work regardless if you have Windows 10 Pro.
In the run dialog box (winkey + R) type "gpedit.msc" (without quotations), hit enter Navigate to Computer Configuration/Administrative Templates/Windows Components/Windows Update Double click on "No auto-restart with logged on users for scheduled automatic updates installations" Enable it and click apply
Ref: Windows 10: Disable automatic reboot for updates
The two other solutions don't seem to be working for me as those registry settings were already set on my computer.
Here is an indirect solution, which is to tell Windows Update not to install updates automatically, just download them, and then prompt for installation. The user can then choose when to install them, and restart then.
Go to the following Registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update
Set the AUOptions value to one of the following values:
1 = Never check for updates
2 = Check for updates but let me choose whether to download and install them
3 = Download updates but let me choose whether to install them
4 = Install updates automatically
I set it to 3.
Source: Microsoft Technet Forums: How to stop Windows 10 from automatically restarting, answer by MaxBak83
Here's a .zip containing a .reg file which SHOULD work even in Windows 10 (though I won't know for sure until the next time M$ pushes a Win10 update which requires rebooting):
http://www.geeksalive.com/NoAutoReboot_Win10.zip
Here's the contents of the NoAutoReboot.reg file, but be sure to read the 00ReadMe.txt, too.
REGEDIT4
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update]
"NoAutoRebootWithLoggedOnUsers"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU]
"NoAutoRebootWithLoggedOnUsers"=dword:00000001
"NoAutoUpdate"=dword:00000000
"AUOptions"=dword:00000004
"AutomaticMaintenanceEnabled"=dword:00000001
"ScheduledInstallDay"=dword:00000000
"ScheduledInstallTime"=dword:00000003
"AllowMUUpdateService"=dword:00000001
Note that for this to be effective you'll need to either restart the Windows Update Service, or just reboot the computer, after installing the registry update.
Winaero.com has provided a way to do it:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AUNoAutoRebootWithLoggedOnUsers and set it to 1 and reboot the device.
For computers with Group Policy, applying the policy User Configuration\Administrative Templates\Windows Components\Windows Update\Remove access to use all Windows Update features with the option Do not show any notifications will completely prevent forced reboots. Windows update on Windows 10 will still remain fully functional.
The registry entries for this policy is HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\WindowsUpdate Create the keys: DisableWindowsUpdateAccess with value 1 DisableWindowsUpdateAccessMode with value 0
This will prevent the task scheduler task in the JaredE's answer from forcing a reboot as well. Even manually running this task will not cause a reboot.
Possible answer, still testing but seems to be working until MS changes these settings in the Task Scheduler.
On another post, "How to disable automatic reboots in Windows 10?", jakethedog references using the Task Scheduler. I expanded on the settings per items in the UpdateOchestrator.
Goto Start and enter Task Scheduler. Goto Task Scheduler Library >> Microsoft >> Windows >> UpdateOrchestrator.
Here you will find items that can be adjusted to cause Updates to behave differently. You can change different properties in each item by right clicking and selecting Properties.
You should see six tabs. Most have parameters that can be set, disabled, or deleted. Use the History tab on each item to see when and what these are processing. Then per tab make the desired changes.
So far, I've only Disabled and not Deleted any parameters. MS may re-add a deleted parameter when the update scans run, whether manually or automatically and replace missing items.
On each item I've adjusted, I've changed the following tabs.
General Tab >> Security options. Changed the user account controlling the item from System to my account. This should help the system account stop overriding changes.
Triggers >> Edit >> Advanced settings. Begin the task: On a schedule. Set Delay task for up to (random delay): to 1 day. Set Stop task if it runs longer than: 30 Minutes. Set Expire: the day you make a change to the item, 15 minutes later than when the change is made and to Sync across time zones. Unchecked Enable.
Actions >> Edit. Rename the Program/script entry. Here, I just changed MusNotification.exe to MNcation.exe and removed the Add arguments option of Reboot. This may be adding to the Event Viewer, I've not checked to see.
Conditions >> Power. Uncheck both entries.
Settings. Set to the following.
Then select OK to close the Properties window and then Right click and Disable the item per item you adjust. Then reboot.
