four computers on same unmanaged switch can't copy files between them - GEEK squad couldn't fix after 3 hours of attempts

original setup was three windows 10 machines with file and printer sharing working, all through ethernet cables to an unmanaged switch. everything was fine until I did the free upgrade to windows 11 on my main computer. My wife's laptop could no longer see the shared folders on my machine. Every search of internet or new suggestion from other more experienced users indicated that my settings SHOULD be correct and she SHOULD be able to see the folders and read/write to them. When I did the free upgrade to windows 11 on my basement computer, that machine also started having the same issues .. but the two windows 11 machines could read/write to each other but the windows 10 machine was blocked somehow. Her laptop CPU was not supported for windows 11 so I bought her a brand new laptop with windows 11 out of the box. Her new laptop will not allow either old/free upgrade windows 11 machines to read/write her "shared" public folders. I had the BestBuy GEEK squad tech come to "fix" it and after 3 hours he said he couldn't find the issue and refunded the service fee. I know this is post is long, but I don't know what to try next.

Have you looked at this tutorial?

W11 24H2 changed the default security settings for File Sharing, which wreaks havoc if you're in a mixed environment with older W10 PC's.

Open a CMD window on each W11 PC as Administrator and run:

Restart the PC.

It's a little unclear to me if your computers cannot see one another or just can't access files on each other. If they cannot see each other, do the following:

Control Panel - Network & Sharing - Change Advanced Sharing Settings
Arrow Left (settings upper left) and do a Network Reset
After rebooting, log on to your wireless network (even if you are using Ethernet)
Then make sure you are set to PRIVATE NETWORK (not public) for Ethernet & WiFi

Do this on each machine.

The computers should now be able to see each other.

You MAY have to do this every time after Tuesday Windows Updates

We've had this same question from folks working with mixed networks.. MS has never made it easy to share.
Try this.
Do this on all systems in network..

add "LanmanWorkstation" as an additional startup dependency for the "Function Discovery Resource Publication" (FDResPub) service, which seems to do the trick. To do this, you simply open an elevated command prompt (i.e. use the "run as administrator" right-click context menu option to start cmd.exe), then execute the following command:
sc config fdrespub depend= RpcSs/http/fdphost/LanmanWorkstation

Reboot each device after executing this command, and the devices should see each other more reliably in Network and File Manager.
Make sure these services are set to automatic and running

DNS-Client – Server

Function Discovery Provider Host

Function Discovery Resource Publication

SSDP Discovery

UPNP Device Host

Windows Defender Firewall


Another method to try

• Open File Explorer.
• In the address bar, type the following: \\computername (replace "computername" with the name of the computer you're connecting to).
• Press Enter.
• Note: You can also use ip address in address bar
• Whichever of these methods allows you to get into the other machine, create a shortcut to it on desktop, and pin that shortcut to quick access. You can then delete the shortcut from desktop.

If that doesn't work, report back and we can try something else.

Just be careful before disabling security settings. At least only do so after properly assessing the possible risks.

antspants said:

Just be careful before disabling security settings. At least only do so after properly assessing the possible risks.

Click to expand...

If you're on a home network with a proper firewall on your ISP router, it's not an issue. The change reverts you to 23H2's previous security settings. Over time, Windows has constantly ramped up the File Sharing security like boiling a frog slowly.

I had to use the \\computer_name until I got the full networking working. My last Windows 10 computer is my laptop, I'm looking for a replacement as that one is at least ten years old and the battery is dead again. I think it's time to replace it.

gunrunnerjohn said:

Have you looked at this tutorial?

See Computers on Network in Windows 11

This tutorial will show you how to see the computers you want on your network in Windows 11. When computers on the same network and workgroup are discoverable, you can see them in File Explorer > Network. This allows you to share what you want among the devices connected to the network...

www.elevenforum.com

Click to expand...

Thanks for the link to the tutorial .. it didn't help my problem but I learned a few things from the tutorial

garlin said:

If you're on a home network with a proper firewall on your ISP router, it's not an issue. The change reverts you to 23H2's previous security settings. Over time, Windows has constantly ramped up the File Sharing security like boiling a frog slowly.

Click to expand...

My understanding is that there are still risks if someone doesn’t understand the caveats and have ensured that:
They’re not exposing SMB ports (e.g. 445) to the internet via port forwarding or UPnP.
They’re only sharing files between trusted devices (e.g. their own PCs, media servers).
They have strong passwords on all local accounts.
Their router firewall blocks unsolicited inbound traffic (albeit usually default in routers).
They’re not running unknown or untrusted software on their LAN.
Guest devices (friends, smart TVs, etc.) are isolated, or they fully trust them.
And more…?

These days you could probably be compromised via a smart fridge, who knows. For those of us who don’t have a knack for networking (like me), it’s at least important to understand the possible risks regardless of how remote they may be?