Wow...thanks for all of the responses. After some considerations and reflections on what I’ve been asked to clarify, I think the most pertinent thing I can do is explain that that a music source (windows media player) seems to have a song playing/paused and I don’t know how to get rid of it...and THAT may be why when I go to System | Network | Networks to highlight and remove the wireless system, it won’t let me, because it shows as being “In Use”.
You can’t remove a WiFi network from Sonos in this area of the Sonos App, it is simply telling you that you have that WiFi connection installed for use with your Sonos Household. In fact the credentials are installed on all your Sonos devices. If you also have one Sonos device wired to you router, then your System is setup for ‘mixed mode’ as @ratty mentions. So your devices may all still be running on SonosNet WM:0, but they could ‘potentially’ switch to your WiFi from time to time depending on the available wireless signal strength etc.
Most here recommend removing ‘mixed mode’ providing you are not using the 2.4ghz WiFi band to run a Sonos “Move” device. To do that you need to go back into the Network settings and go to “Wireless Setup” and go from the 'reset’ button to remove the WiFi credentials from all speakers and ‘force’ them to only connect via their in-built SonosNet wireless mesh/lan connection instead.
I think that is hopefully what you are seeking to do here? However your posts are not too clear.
I’ll try cycling the power, etc., without the ethernet cable plugged in….that might “clear” everything, so I can then plug the ethernet cable back in and go remove the WiFi.
BTW, just thought I’d get better access to music sources on my ethernet desktop computers if the SONOS Ones were set up via ethernet….but perhaps it doesn’t really make any difference.
If you are looking to actually switch off the Wireless/WiFi card hardware within all your speakers, then whilst that is possible to do in a different area of the Sonos App, it is not recommended that you do that, even if you do wish to cable All your speakers to the LAN. It is usually best to leave the internal WiFi hardware enabled. If your speakers are working, then I would “let sleeping dogs lie” and leave those things as they are.