Why Windows 11 File Sharing Breaks
File sharing in Windows 11 relies on the Server Message Block (SMB) protocol, network discovery, and the Credential Manager. When any of these breaks — due to a Windows Update, a Group Policy change, or a firewall rule reset — you get errors like "Windows cannot access \\PCNAME", "You do not have permission to access this folder", or shared computers simply not appearing in File Explorer. This guide covers every fix, including the SMB 1.0 removal issues, the 2026 May update (KB5058411) regression that broke LAN discovery for some users, and the Windows 11 Pro vs Home SMB signing difference.
Fix 1: Enable Network Discovery and File Sharing
Network Discovery is disabled by default on Public networks and can be silently reset by Windows Update.
Step 1. Open Control Panel → Network and Sharing Center → Advanced sharing settings.
Step 2. Under Private networks, enable both Turn on network discovery and Turn on file and printer sharing.
Step 3. Expand All Networks and enable Turn off password protected sharing if you are sharing within a trusted home or office network.
Step 4. Click Save changes.
Step 5. Ensure both PCs are on the same Network Profile (Private, not Public): Settings → Network & Internet → click your connection → set to Private.
Fix 2: Enable the Required Windows Services
Several services must be running for file sharing: Function Discovery Resource Publication (FDResPub), SSDP Discovery (SSDPSRV), UPnP Device Host (upnphost), and Server (LanmanServer).
Step 1. Press Win + R, type services.msc, press Enter.
Step 2. For each service in the list above: right-click → Properties → set Startup type to Automatic → click Start if not running.
Step 3. Verify with PowerShell:
Get-Service FDResPub, SSDPSRV, upnphost, LanmanServer | Select Name, Status, StartTypeFix 3: Fix Windows Firewall Rules for SMB
Windows Update (particularly KB5058411 in May 2026) has been reported to reset firewall rules, blocking TCP port 445 (SMB) on the local subnet.
Step 1. Open PowerShell as Administrator and re-enable the SMB firewall rules:
Enable-NetFirewallRule -DisplayGroup "File and Printer Sharing"Step 2. Verify port 445 is open:
netstat -an | findstr 445You should see 0.0.0.0:445 LISTENING.
Step 3. If a third-party firewall (Bitdefender, Norton, Kaspersky) is installed, temporarily disable it to test. If sharing works with it off, add a LAN exception rule.
Fix 4: Re-enable SMB 2.0 (and Avoid SMB 1.0)
Windows 11 22H2 and later removed SMB 1.0 entirely. If you are trying to connect to a very old NAS (pre-2012) or a Windows XP machine, it will not work without SMB 1.0. However, for modern Windows-to-Windows sharing, ensure SMB 2.0 is enabled.
Step 1. Check SMB status:
Get-SmbServerConfiguration | Select EnableSMB2ProtocolStep 2. If SMB 2 is disabled, re-enable it:
Set-SmbServerConfiguration -EnableSMB2Protocol $true -ForceStep 3. For legacy device compatibility only (not recommended for security): enable SMB 1 via Windows Features → Turn Windows features on or off → check SMB 1.0/CIFS File Sharing Support.
Fix 5: Fix Credential Errors
"Windows cannot access \\PCNAME" with error code 0x80004005 or 0x80070035 is almost always a credentials issue, especially when the target PC uses a Microsoft Account.
Step 1. Open Credential Manager (search in Start menu).
Step 2. Under Windows Credentials, remove any old entries for the target PC's hostname or IP.
Step 3. When reconnecting, use the format PCNAME\LocalUsername (not the Microsoft Account email). Find the local username under Settings → Accounts → Your info on the target PC.
Step 4. On the target PC, ensure the account is in the correct local group: Computer Management → Local Users and Groups → Groups → Users (for read access) or Administrators.
Fix 6: Fix the SMB Signing Mismatch (Windows 11 Pro vs Home)
Windows 11 Pro enforces SMB signing by default since 2023. Connecting from a Home edition PC to a Pro edition server can fail silently if signing is mismatched. Error: "The network name cannot be found" or "An unexpected network error occurred."
Step 1. On the server PC (the one being connected to), open PowerShell as Administrator:
Get-SmbServerConfiguration | Select RequireSecuritySignature, EnableSecuritySignatureStep 2. To disable mandatory signing (for local LAN only — not recommended on untrusted networks):
Set-SmbServerConfiguration -RequireSecuritySignature $false -ForceStep 3. Alternatively, enforce signing on the client too for a consistent secure setup: on both PCs run Set-SmbClientConfiguration -RequireSecuritySignature $true -Force.
Fix 7: Use IP Address Instead of Hostname
NetBIOS name resolution (used when you type \\PCNAME) frequently fails when mDNS or LLMNR is blocked by a router or VPN.
Step 1. Find the target PC's IP: on the target PC, run ipconfig and note the IPv4 address (e.g., 192.168.1.150).
Step 2. In File Explorer on the connecting PC, type \\192.168.1.150 in the address bar instead of \\PCNAME.
Step 3. If this works, the issue is name resolution. Fix it permanently by adding an entry to the hosts file on the connecting PC:
192.168.1.150 PCNAMEEdit the file at C:\Windows\System32\drivers\etc\hosts as Administrator.
If Windows 11 file sharing is still not working after these fixes, book a CloudHouse Pay-Per-Ticket Support session — our engineers diagnose SMB and LAN sharing issues quickly.
