monline

You can allow guest access to Samba shares using a combination of the "public = yes" (or the "guest ok = yes"), the "guest account = <account>" and the "read list = user1, user2, group1" config parameters in smb.conf. However this works only with Windows 2000 and recent versions of Windows clients, they can successfully access the share without a valid username or password.

But Windows NT (v4) clients fail, they present a username+password prompt to the user how tries to access the share. Actually I don't know the internals of the different behaviour of old NT and newer Windows versions while accessing shares, but the fix is to change the default "map to guest = Never" value to "map to guest = Bad User" in smb.conf.