What I recommend is to indeed disable that adapter prior to running Sonar, then going into the ASIO Control Panel for your audio interface, and changing the ASIO Buffer Size there.
Some interface UI screen's are accessed through Preferences>Audio>Driver Settings, by hitting the ASIO Control Panel button, but some vendors do not respond to that, and instead they usually have a program running and minimized down to the Windows System Tray, which is down in the right-bottom corner of your Desktop (you may have to hit the little arrow to expand your hidden icons).
I have only ever seen those 2 ways of getting to the audio interface's UI screen, so one of those should work.
As far as what to set it to, some of the UI screens use ASIO Buffer Size, and some have 'Number of Samples', and some have a slider and a number. They all control the buffer size, it's just different mechanisms for doing so.
If you see ASIO Buffer Size, set it to 128. If you see Number of Samples, shoot for around 220-230 samples, or whatever is around or under 250 samples. If it is a slider, try moving it down a bit, it if is now on 6 move it to 4 or 5 (you can always make this change and go see what it does to your ASIO-reported Input Samples and Output Samples in Sonar's Preferences>Audio>Driver Settings, in the reported latency section, and go back and further adjust the slider one way or the other - until you get it set to around 220-230 or so).
What you want to end up, as a reasonable balance, is to have an ASIO-reported Total Roundtrip Latency of around 9-10 milliseconds, which will give you good sound quality without really hearing any dropouts.
The above is my recommendation for when you are RECORDING. You will have to make your buffer bigger - possibly up to around a buffer size of 1024, instead of 128, when you are doing mixing/mastering, but for recording use the above settings and with your Wi-Fi also disabled you should be OK.
SOOOO, give the above a shot and please post back on the results, or ask more questions if you need me to take another stab at explaining any of what I posted.
Bob Bone