Within windows update in control panel is there any option to cancel, there generally will be at the time when updates are being downloaded but I'm not sure if there is still such an option for cancellation after download has finished and updates are waiting for a restart so they can install. It might be that the only possible method is to restart then find out afterwards what was installed and remove it then. But I suggest you try to wait longer and see if anyone can give further advice. Maybe if the updates are stored somewhere on the system before installng their files could be renamed or something s they wouldn't be installed, But I cannot be sure if this would work, it might instead damage important system files severely.
If you had a system image you could restore to that, but it would be easiest to first allow the restart, see what updates they were and remove them that way instead, most of the time updates can be removed like this, a system mage would only be needed for the few updates which cannot.
The below concerns your problem in general, and is more a guide to working out why windows update's settings changed and stopping it happeneing again. The below won't very likely be of help in dealing with your present situation where you have updates already downloaded and waiting fro restart.
On the subject of the update settings being changed I have heard of this before, but never seen it personally. I can quite imagine how dangerous this could be, updates are something which many users need to be very careful about which they install, the setting being changed from the user's chosen setting is very concerning.
I would suggest you look to see if you have any "software updater" programs present, they might be parts of certain antiviruses, parts of manufacturer's built in "general support" software, or perhaps parts of some kind of "optimizer" program (optimizers are generally ineffective, and they can be damaging in some circumstances. If you have one you might well want to uninstall it.). Some such things could perhaps change windows update settings, if you have any such products search in their settings and see if they have a software updater in them, if so turn that bt of the program off.
I suggest you also look at which windows updates have been installed in the recent past, have any of those many updates to wuauclt that have been coming out since summer been installed on your machine?
Other tips are to look for services in the "services" tab of task manager, click the link "open services" and look down the list which is listed. See if there are any thrid party software updating services running, also look for services from the manufacturer, don't disable them yet, but report what they are on a post here. Also look for the windows update service in the services list, it should be set to "manual trigger start" for users wanting "check automatically but ask me whether I want to download".
One other thing, is KB3013816 installed? If so it would be a long time ago, it might be able to cause updates to switch unwelcomely to fully automatic mode.
Edited by rp88, 10 February 2016 - 03:20 PM.
Back on this site, for a while anyway, been so busy the last year.
My systems:2 laptops, intel i3 processors, windows 8.1 installed on the hard-drive and linux mint 17.3 MATE installed to USB