At work I have been asked about not being able to connect to shared folders (Samba) since somewhere around Windows 10, and recently the questions from people who have updated to Windows 11 have increased as well.
Let’s check the items below!
Enabling the SMB1.0 client
On Windows 11 the “SMB1.0 client” is disabled in the default settings.
The “SMB1.0 client” standard is old and vulnerabilities have been reported for it, so Microsoft disables the “SMB1.0 client” from a security point of view, and that accounts for most of the cases where the connection fails
Enable the SBM1.0 client
Setting the network profile to private
Under Settings → Network & Internet → Ethernet (or Wifi),
if the network profile type is set to public, change it to private
When guest access is locked
If the error 非認証のゲストアクセスがブロックされているため… appears on the error screen when you cannot connect, open the registry editor (gpedit.msc) and, from Local Computer Policy,
move to [Computer Configuration]->[Administrative Templates]->[Network]->[Lanman Workstation],
then open Enable insecure guest logons in the right pane and enable it.
A restart is required afterwards