I have a standard Sonos system with several Play 3 speakers. My iTunes library is on my PC. It works fine until I reboot my PC. After the reboot, (my IP stays the same) the Sonos speakers can't play my music, and they report that the library at \\M1\iTunes can not be located (or similar). My PC is on, connected to network and working fine. If I go to my computer and start the Sonos Controller For PC, then my speakers will play my library fine. If I close the Sonos Controller app on my PC, the speakers will continue to play fine. For days, until I reboot my PC again. The thing is, that I don't see a share on my PC named iTunes. Even when it is working, if I use Net Share to list out the shares on my PC, it doesn't exist. So I'm wondering, how DO the speakers see the music on my PC anyway? Is there a service on my PC and a special server for this, or something else? I thought it was standard windows file share since a lot of people are using a NAS, but again, I don't see the share on my PC. Why does it work after I start and close the controller on my PC? It's gotta be something simple I'm missing here. I searched the forums and I see some questions that are close to this but I couldn't find an answer. Thanks for any assistance.
Best answer by MikeV
Sonos recently switched from using SMB, which uses the operating system's "File Sharing" functionality, to having their own music library service that runs in the background on your computer. Their music library service uses HTTP to "stream" music from your computer to your Sonos speaker(s) that are playing from your music library. Folders on your computer that you share to Sonos won't show up in the shared folders listing for Windows, since they aren't using Windows' file sharing services.