How to Fix NAS errors with SMB in Windows 11 24H2

The 24H2 update for Windows 11 has introduced new security measures that might cause issues when mapping third-party network storage (NAS) drives. These measures include mandatory SMB signing and the disabling of guest access on Windows 11 Pro.

While these changes enhance security, they can disrupt connections with NAS devices that do not support SMB signing or depend on guest access for straightforward setup.

How to solve NAS problems with SMB in Windows 11 24H2

Although it has taken longer than expected, a solution to this problem is now available. For security reasons, Microsoft recommends users follow these steps:

1. Consult your NAS vendor’s instructions to enable SMB signing in the device management software (if supported).
2. Similar to step 1, consult your NAS vendor’s instructions for disabling guest access in the management software.
3. Set up an authentication username and password on your NAS for secure access.
4. If you cannot enable signing, disable guest access, or use usernames and passwords, consider updating your NAS firmware to a supported version.
5. If updating the firmware does not resolve the issue, you may need to replace your NAS with a model that supports the necessary security features.
6. Disable the SMB client signing requirement:
   1. In the Start menu search, type gpedit and launch the Edit Group Policy app (i.e. Local Group Policy Editor).
   2. In the console tree, select Computer Configuration > Windows Settings > Security Settings > Local Policies > Security Options.
   3. Double-click Microsoft Network Client: Digitally sign communications (always).
   4. Select Off > OK.
7. Disable guest fallback protection:
   1. In the Start menu search, type gpedit and launch the Edit Group Policy app (i.e., Local Group Policy Editor).
   2. In the console tree, select Computer Configuration > Administrative Templates > Network > Lanman Workstation.
   3. Double-click Enable insecure guest logins.
   4. Select On > OK.

Microsoft recognizes that these steps may not always be feasible for all users. As a last resort, they offer instructions for disabling SMB signing and guest access protection. Here are the steps for those who need an alternative solution: