Windows 11 24H2 Breaks File Sharing

Windows 11 24H2 breaks access to network shares which use guest logins, because Microsoft have decided to disable guest logins by default. This can be re-enabled easily:

1. Open the Run window (Win + R) and type gpedit.msc to open the Local Group Policy Editor.
2. Navigate to Computer Configuration > Administrative Templates > Network > Lanman Workstation and select Enable insecure guest logons.
3. Enable it, click OK and exit Group Policy Editor.

You can also do the above through PowerShell (preferred method from August 2025 onwards):

1. Right click the Start menu and go to Terminal (Admin).
2. Enter the following command:
   set-SmbClientConfiguration -EnableInsecureGuestLogons $true -Force

More recently (May 2025 onwards), fresh Windows 11 24H2 installations seem to require SMB connections to have a security signature. This causes problems when making connections to Samba shares on Linux. You need to change the value of RequireSecuritySignature through PowerShell:

1. Right click the Start menu and go to Terminal (Admin).
2. Enter the following command:
   set-SmbClientConfiguration -RequireSecuritySignature $false -Force
3. You can check the full SMB configuration with the following command:
   get-SmbClientConfiguration