Unable to access share folder after updating to latest win 11

Hello Ohidul Mallick, Please try opening the Registry Editor, typing regedit in your Start menu, and navigating to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa. In this folder, look for a value named ForceGuest. You need to double-click this value and change its data from 1 to 0. This single adjustment shifts the underlying security model from "Guest only" to "Classic," ensuring that your local users authenticate as themselves rather than being stripped of their credentials at the door. If you are running the Pro version of Windows, you can achieve this exact same result by opening the Local Security Policy tool, navigating to Local Policies, selecting Security Options, and changing "Network access: Sharing and security model for local accounts" to the Classic setting.

One possible cause is that your systems might be stubbornly holding onto the previous, failed authentication attempts. Windows uses a digital vault called the Credential Manager to save network passwords, and a corrupted or outdated entry here will silently override your manual typing, repeatedly feeding the destination machine a bad token. Open the Start menu, search for Credential Manager, and click on the Windows Credentials tab. Carefully review the list and click "Remove" on any entries that reference the names or IP addresses of the computers you are trying to connect to. Once the vault is cleared and the registry is updated to the Classic security model, restart your computers to establish a completely clean handshake.

VPHAN

Hi Ohidul Mallick,

To resolve this domain mismatch, you must explicitly instruct the network connection to authenticate against the destination computer's user database. When the credential prompt appears, you need to prefix your username with a period and a backslash, typed exactly as .\ followed immediately by the username of the account on the target machine. This specific syntax tells Windows to look at the local security authority of the computer hosting the shared folder. Alternatively, you can type the actual computer name of the target machine, followed by a backslash, and then the username.

Furthermore, you must verify that the user account you are attempting to log into on the destination machine actually has a password assigned to it. The Windows local security policy dictates that network logons are strictly blocked for any user account with a blank password to prevent unauthorized network crawling. If the account on the updated Windows 11 24H2 system currently uses a blank password or a PIN without a core password, you must go into the system settings and assign a standard password. Once the target account has a designated password and you utilize the backslash prefix to direct the authentication context, your shared folder access will be fully restored.

VPHAN

Hi

Thank you for your response.. But I have executed both the commands on both 25h2 systems but still same issue.. When trying to access a share folder it Constantly asking for username and password when trying to access share folder and when entering id & pass it showing "username or password is incorrect"

Hello Ohidul Mallick,

Your file sharing issue stems from intentional security enhancements introduced in the Windows 11 24H2 update, which fundamentally alters how the Server Message Block protocol handles local network traffic. Microsoft now mandates network signing by default on all connections, acting as a cryptographic seal to prevent data tampering, and guest authentication is strictly blocked. When you attempted to modify the registry using the path HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters to set AllowInsecureGuestAuth, the connection still failed because the newly updated 24H2 host system is actively rejecting these unsigned, unauthenticated guest requests regardless of your client-side registry overrides. Older systems and guest accounts simply cannot negotiate these new mandatory security signatures.

To resolve this while maintaining the integrity of your network, the recommended approach is to completely transition away from guest network access. You should create dedicated local user accounts with strong passwords directly on the newly updated Windows 11 24H2 machines and explicitly grant those accounts permission to access your shared folders. When you attempt to connect from the older systems, Windows will prompt you to enter these specific credentials, which successfully satisfies the cryptographic signing requirements and securely restores your access across all machines.

If your computers operate on an isolated, strictly private home network and you absolutely must rely on legacy guest access, you can manually revert these new security protocols. You will need to open PowerShell as an Administrator on your Windows 11 24H2 systems and execute the command Set-SmbServerConfiguration -RequireSecuritySignature $false followed by Set-SmbClientConfiguration -RequireSecuritySignature $false. This instructs the operating system to stop demanding the cryptographic seal on file sharing traffic. After confirming both prompts and restarting your systems, your previous sharing configuration and the insecure guest logon registry edits you previously applied should begin functioning exactly as they did before the update.

Hope this answer has brought you some useful information. If it did, please hit “accept answer”. Should you have any questions, feel free to leave a comment.

VPHAN