Unable to to Disable Defender Real Time Protection

Hi
I installed the April 2018 Win 10 Update today which has resulted in my CPU constantly working 15% higher due to the Antimalware Service Executable. I’ve tried to disable Defender as suggested by Microsoft but its instruction was to go to Settings / Update & Security / Windows Security / Virus & Threat Protection / Virus & Threat Protection Settings. This should have given me access to switch Real Time Protection off, but the final ‘Settings’ option was not available – see screen shot.

Any ideas please?
Many Thanks

Thanks for that Brink. I have just added Eset Nod32, but the System Update happened much earlier today.
How can you tell that Defender Real Time Protection is off from that screen shot? What Im trying to do is to reduce the constant high (no apps running) CPU usage as shown in this new screen shot.

Cheers, I'll give that a go! - its deafening!

No success. I tried the Powershell method using both (turn off' options and both said I don't have enough permissions to perform that task. I also noticed something similar when going into the 'Virus & Threat Protection' part of Windows Security. I am the Administrator on the PC (the only user) and have checked that its still says this.

I feel as if Im running out of options. If I cant disable this Real Time Windows protection, do you know if I can reset my system back as it was before the update ran this morning?

Thanks

I downloaded the .reg file and executed it, and rebooted, but the Win Defender Anti Virus is still running.

Do you know if a system restore would get me back to the way things were this morning, when it was quiet in here and there wasn't blood running out of my ears!!!
Thanks.

And then finally after 5 howling hours, it all of a sudden stops!

Thats how it should be! Fingers crossed its as well behaved in the morning!

Thanks very much for your help on this Brink, much appreciated.