Ethernet connection for best sound quality

Don’t use a computer.  A dedicated streamer is $$$ very well spent. 

1) A streamer

Look at the Martin Logan Unison which functions as a preamp, a streamer, and has ARC room correction, on sale at 50% off:

https://www.martinlogan.com/en/product/unison

A dedicated streamer, keep the PC out. The better quality the streamer (as all audio components), the better  If your system is too far from your router modem you can use a wall wart wifi extender and a short Ethernet cable from there to your streamer. My systems run this way (see under my UserID.

You don't need a streamer unless it's inconvenient for you to use the PC. A streamer is basically a small computer with some software installed to enable streaming. You could download this software yourself or enable it (depending on what OS is on the PC).

You also don't need a fancy Ethernet card or shielded cabling either. If you own a cell phone or use wi-fi and Bluetooth, or can receive TV / radio stations, your audio components are already bathing in a sea of RF signals.