Hello Logan,

Thank you for reaching out with your question regarding insecure guest logins in Windows 11 24H2.

Background:

Microsoft has been progressively increasing the security measures in Windows, and disabling insecure guest logins is one of those steps. Insecure guest logins can pose a significant security risk because they allow access to network shares without requiring a username or password. This change aligns with the security enhancements seen in Windows Enterprise editions.

Your Situation:

After updating to Windows 11 24H2, you found that connecting to network shares without requiring a login (everyone access, password protected sharing turned off) no longer works. Shares with a password and those configured in group policy to allow insecure guest logins function correctly.

Explanation:

Based on the behavior you described, it seems Microsoft is indeed defaulting insecure guest logins to disabled in Windows 11 24H2. This change would enhance security by preventing anonymous access to network shares.

Steps to Address the Issue:

1. Enable Insecure Guest Logins via Group Policy:

• Press **Win + R**, type gpedit.msc, and press Enter to open the Group Policy Editor.
• Navigate to **Computer Configuration** > **Administrative Templates** > **Network** > **Lanman Workstation**.
• Double-click **Enable insecure guest logons** and set it to **Enabled**.
• Apply the changes and restart your computer.

2. Enable Insecure Guest Logins via Registry Editor:

• Press **Win + R**, type regedit, and press Enter to open the Registry Editor.
• Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters.

• If the AllowInsecureGuestAuth entry does not exist, right-click and select **New** > **DWORD (32-bit) Value**, and name it AllowInsecureGuestAuth.
• Set the value of AllowInsecureGuestAuth to 1.
• Close the Registry Editor and restart your computer.

3. Consider Alternative Security Measures:

• Instead of enabling insecure guest logins, consider setting up password-protected sharing for better security.
• Ensure that all users have appropriate permissions to access the necessary shares.

Best regards,

Rosy

Within the latest “Windows 10 Fall Creators Update” the Guest access in SMB2 is disabled by default.

You can change this setting within your group policy settings.

Right click the Windows Icon at the bottom left of the task bar, or select the windows key + r

Within the run box, type “gpedit.msc”

Within the local Group Policy Editor, select “Administrative Templates”

Select “Network”

Select ”Lanman Workstation”

Double click “Enable Insecure guest logons” option

Tick the “Enable” option

Select OK

If this did not work consider checking this registry key too:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\AllowInsecureGuestAuth

It should be set to 1 for your case. (Credits: zhqiat)

Note: By enabling insecure guest logons, this setting reduces the security of Windows clients. https://support.microsoft.com/en-us/help/4046019/guest-access-smb2-disabled-by-default-in-windows-10-server-2016