Which issue are you dealing with? You mention two, one being unable to reach your speakers at all, the other your speakers not recognizing your local library. 
 

For the first, I’d certainly try wiring one or more Sonos devices to your router with an Ethernet cable, snd see if it connects. If not, it would really be helpful to tell us which Sonos OS you are using, which device your controller is on, what OS is running on that device, and potentially which Sonos devices comprise your Sonos system. It might be helpful to mention how they currently/normally are connected to your LAN.

For the latter issue, in S2, Sonos has changed the way that their new app accesses audio from shared libraries on the local network. The previous S2 App supported SMBv1 and HTTP protocols for file sharing, but these have known vulnerabilities and are no longer used by Microsoft, Google, Apple, Amazon etc. and all these companies, including Sonos, have now shifted to using SMBv2 (or higher) file sharing.  You may need to upgrade your shares… see these links depending on how you share your library tracks…

For MacOS users, see this thread.

For Windows users, see this thread.

Sonos sent out notices both in the S2 app, and in email, about these changes. They also updated the FAQ to reflect the update. While they have stated that the local library system continues to be worked on, I do not expect them to resume use of HTTP or SMB v1, so if your computer uses them, I’d recommend re-adding your share, as is indicated in the controller, where it says ‘We’ve made security changes to supported libraries. You may need to re-add your library”.

If you’re having trouble finding this area in your controller, open the S2 controller, click on the gear icon at the upper right of the screen, then the word ‘Manage’ under it. Next, click on ‘Music Library’, and the page to enter/modify your local library will come up.

If you continue to have issues, I would recommend that you call Sonos Support to discuss it.

I have already tried to hard wire one of my speakers. No change. I can’t get into the program to check but I tried two different install files. Sonos_79.0-52294.exe and Sonos_83.1-61210.exe My PC is a Dell running Windows 10 Home edition I have two Play 3, four Play 1, a sound bar, and a sub-woofer. They are all wireless on wifi.

Helpful, certainly. Have you called Sonos Support directly to discuss it?

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

I don’t use the Windows controller myself, but as I recall, you do have to set the OS to ‘Private’, and not ‘Public’, but I don’t have any real knowledge, especially if you’ve tried wiring a speaker temporarily. 

Unfortunately, also because I don’t use the Windows controller, I have no idea if those files are S1 or S2 controllers, but the folks at Sonos will. 

By far the common issue on Windows for device discovery problem is networks that are marked as “Public”, needs to be “Private”. Always for WiFi, sometimes for Ethernet also.

Try my Windows app, it will tell you if this is the problem: https://apps.microsoft.com/detail/9nblggh4x6j0