Hi! There was a mail with a very similar problem recently. I have a samba PDC with one share, and a win2003 machine (which is in the samba's domain) where a service is running, which for some reason tries to access this share as the system account, which maps as guest on the samba side, and gets rejected. I can see this line in the log: [2011/12/12 11:47:14.959209, 3] libsmb/ntlmssp.c:747(ntlmssp_server_auth) Got user=[] domain=[] workstation=[ABC] len1=1 len2=0 So samba knows about that this is the machine called ABC. Is it possible to allow this empty user from the ABC machine to access the share? This is the share part of my config: [abcdata] path = /path/to/abc valid users = abcuser read only = No I have not much control over this service, so I cannot make it use a proper username/password. And I don't want to open this share for guests. Any help or hint would be very appreciated! Thanks, Zsombor