Unlike yesteryear, it's no longer as simple as turning off updates, you now should edit your registry as well.
Here's a couple if sites that spell it all out.

http://www.howtogeek.com/224471/how-to-prevent-windows-10-from-automatically-downloading-updates/

This one shows you how to edit registry. But there is no guarantee it will hold, you need to check it every few months, Win 10 is sneaky.

https://4sysops.com/archives/disable-windows-update-in-windows-10/

Another machine, a quad core, was hit with a 20 minute, multiple boot update.

It's got absolutely NOTHING to do with processor speed, or HD speed or RAM - all my computers are running very fast SSD drives, at least 8Gig of RAM, and will cold boot to 100% -ON- ready to work in less than 15 seconds.  A couple of them booted WIN-8 in just 8 seconds, when not connected to the servers.

20 minutes of updates for a stripped down, machine with everything not needed removed, and 1 week of not attached to the Internet is really ridiculous, IMO.  This machine has just ONE purpose - which worked just fine under WIN-8.0

Well.... enough of that Windows 10 CRAP!

The rollback has begun, working on the first machine now - these 20-30 minute "updates" are screwing up work!

You'd think, when it gives the shutdown options:

Update & shutdown
Update & reboot

either one would -complete- the update and be DONE, right?   

WRONG!  (...thought I heard it say, "ha-ha big guy, I got you by the nads!...")

on the next cold start, or reboot...then... it .... does.... the .... real.... time.... consuming.... up-date.

Meanwhile, you're standing around, 20-30 minutes or more, waiting to be able to use your PC!  And when it's finally done, before you say, "Whew, glad that's over....!"   The same update message appears again when you shut down.... and... reboot.... just... when... you.... need... it .... most.... you're .... on... hold... again!

And 20-30 minutes is with FAST solid state drives - it's 45-90 minutes with a standard hard drive!  No joke, I've suffered through it 3 times with an Intel I5 machine, 8gig ram, 500G SS hard drive (20-30 min) and 2x with an older machine with a non-SS drive... 90min followed by a 45 min reboot/startup.... when I really needed the machine for a 5 minute test!

I made a point of plodding thru the registry to turn OFF updating, but made the mistake, "meh, what could it hurt, I'll run an update..."
It took 2 reboots for that machine to update, and then a week later, same damn thing, again!

Like a stealth update.... waiting until I needed the laptop the most... lying in wait to get in a really good bitch-slap!

I am reloading windows 7 and 8 on every machine I switched, asap and be done with this crap.