I consider myself to be one of the more lucky ones because I have never had to disable anything, not even onboard audio (I use onboard audio for PC= you tube, media player, exc). Only when I worked on a laptop I disabled my wireless card because of interference. but this Intel I7 I have, I did nothing except create a power plan. that's it. I use my USB soundcard (Focusrite) and Midi CS plugged in to my Focusrite.
I have 2 sets of speakers for USB soundcard and set of PC speakers for PC.

dlion : the key to that motherboard running flawlessly is  the correct chipset/inf. driver and there are only 2 !
https://www.asus.com/us/Motherboards/P9X79/HelpDesk_Download/
 
Windows 10  Version 10.0.27 .. i would try this 1st'' if your on win7 get 7 drivers !
Plan B : Version 10.1.2.8 
notwithstanding the drivers are old .. they are the correct drivers for you board.. Intel's latest will make a mess of your system !!!
the last bios is P9X79 BIOS 4701
Improve system stability.  again key to your motherboard running perfect and it will ... ive worked on many ..good luck !
     

So, can you only obtain the beta driver by invitation? I am having a few dropout problems with my 6i6 and would very much like to try an updated driver to see if that is the issue. I searched the web for the 4.26 beta driver without any luck.

have to contact their techs. their online chat is quite good, and they send you a copy of the chat by email. a running dialogue of what has been tried... next time you contact them, they look you up, read the previous chat, and continue forward.

Ruckman65
So, can you only obtain the beta driver by invitation? I am having a few dropout problems with my 6i6 and would very much like to try an updated driver to see if that is the issue. I searched the web for the 4.26 beta driver without any luck.

http://beta.focusrite.com/

Careful on that site and make sure you get the proper driver. It takes a while for that page to open.
 
Per my post above, I ultimately gave up on the 18i20 after 3 weeks of going back and forth with tech support. Either I got a bad unit or it just didn't like my system. It would randomly lose connectivity with SONAR, I would also get stuck MIDI notes but the worst was when engaging the transport with either audio or MIDI I would get a high pitched squeal and no sound from SONAR. It got to a point where it made my system for recording and playback unusable. I'm using a Behringer 1820 without any of the problems I had with the Focusrite...It doesn't go as low buffer wise (the lowest setting is 64 samples) but it is much more stable for me at that setting then the 18i20. Shame really, I had high hopes for the Focusrite, but in my situation I needed stability and not wasted time with beta drivers or buggy software.
 
 

I run my 1st gen 6i6 on the latest beta driver. It works flawlessly. I can record @16 samples, although latency doesn't matter since I started to monitor signal through a real tube preamp.