My PC has a Intel I7-6000 3.4 GHz CPU and the Performance Modules shows 8 threads/cores (forgive the terminology gaff there)
 
The first thread in the 'Audio Processing' meters is always the one that's the highest and if there's  any audio dropout it goes into the red and soemtimes can even go up when nothing is playing which leads me to believe there could be some background process in W10 that could affect this
 
Is there a tutorial that shows how to optimise W10 for music production and is there an program that can offer a quick way to switch/reboot from a 'Normal' boot up to a DAW optimised one 

If you look in preferences there is an option to allow core balancing.  See if it is checked. If it is not then check it. If it is uncheck it and see if one way or the other makes a difference.
 
https://www.cakewalk.com/...p=NewFeatures.017.html

By default the primary thread is additionally used for cooking audio to process as well as actual audio processing that's why its load is higher. You can play with the ThreadSchedulingModel settings in aud.ini to see if it improves the load balancing for you. Setting it to 2 sets it into a more strict producer-consumer mode where there is a dedicated thread for cooking the audio. On a multicore system with more than 4 physical cores this could lighten the load on the primary thread and give you some extra headroom. The bottom line is you only have as many cores as available by the CPU so there is a trade off to everything. 
 

https://bitsum.com/parkcontrol/

I have Sonar Professional, not SPLAT, so I didn’t have the load-balancing feature.

I’ve been using this to “unpark” my CPU cores, which Windows apparently does by default. Made a big difference in balancing CPU load. Have been using for over a year with no problems. I started with the free version then got the pro version ($4.99 US). Might check it out.

And they even offer Lifetime Updates !!
 
 

Windows does not have a low latency mode like Ubuntu studio.

If you hit the start button and x together on a laptop you can set the computer into presentation mode which will block some windows processes. I always do this on laptops.

Power mode should be highest.

USB selective sleep disabled.

Network interface cards selective sleep disabled.

Are you using synthesizers with lots of voices when you drive up the first core?

https://youtu.be/d-F6xevvhFs

https://youtu.be/0Bimx_qs7Jk

There are several optimisations you can or should make in Windows. The most important are the power saving features. This includes CPU throtteling, HDD sleeping and USB sleeping. Also disabling some non-essential background processes that may be a part of Windows or other software you have installed. Make sure no tasks are running while you are working e.g. virus scanners, backups etc.
 
Enabling Windows God Mode is very handy for quickly getting to the deepest settings, but use it carefully! Simply create a new folder on your desktop and name it {ED7BA470-8E54-465E-825C-99712043E01C} (including the braces). That will give you an icon that you can now click on to get to a categorised list of advanced settings such as all the power saving settings that you want to disable.
 
It's worth searching Google for "optimizing windows 10 for audio production" for all the fine details.