Windows 11 24H2 Network Share Access Issue

Contents

After upgrading to Windows 11 24H2, users may encounter issues accessing network shares on other devices such as Synology NAS systems. When attempting to access shared folders, the following error message appears:

You can’t access this shared folder because your organization’s security policies block unauthenticated guest access.

This issue occurs because Windows 11 24H2 implements stricter security policies that block unauthenticated guest access to network shares by default.

Environment

  • Windows 11 24H2
  • Accessing shares on non-Windows devices (e.g., Synology NAS)
  • Error occurs when attempting to access network shares through File Explorer or mapped drives

Root Cause

Windows 11 24H2 introduces enhanced security measures that disable insecure guest logons to SMB shares by default. This change is part of Microsoft’s efforts to improve security across the Windows platform, but it can prevent access to network storage devices that rely on more permissive authentication methods.

Resolution

The issue can be resolved by modifying the Windows Group Policy to enable insecure guest logons:

  1. Press Win+R to open the Run dialog
  2. Type gpedit.msc and press Enter to open the Local Group Policy Editor
  3. Navigate to: Computer Configuration > Administrative Templates > Network > Lanman Workstation
  4. Locate and double-click on “Enable insecure guest logons”
  5. Select “Enabled” and click “Apply” then “OK“
  6. Close the Group Policy Editor

Note: A system restart is not required for this change to take effect.

Alternative Solutions

If the above solution is not viable or doesn’t resolve the issue, consider these alternatives:

  1. Use specific credentials when connecting:
    • When mapping the network drive, check “Connect using different credentials”
    • Provide appropriate username and password for the remote device
  2. Update SMB settings on the NAS device:
    • Access your NAS administration interface
    • Set SMB protocol to version 3 if available
    • Review and adjust authentication settings
  3. Store credentials in Windows Credential Manager:
    • Open Control Panel > Credential Manager
    • Add Windows credentials for the specific network address
    • Enter appropriate username and password

Security Considerations

Enabling insecure guest logons reduces the security of your system by allowing potentially unauthenticated connections to network resources. If possible, consider implementing one of the alternative solutions that maintain higher security standards.

References