We have a network of 20+ computers, mostly Macs. Our NAS server, "ppserver", has SMB enabled. The problem machine runs Vista Ultimate SP1. When trying to directly connect to \\ppserver, I get "\\ppserver is not accessible. You might not have the permission to use this network resource. Contact the administrator of this server to find out if you have access permissions. An unexpected network error occurred." Another machine with XP Pro can access the server fine. It can also access shared folders on the Vista client.I get the same error with \\[the server's IP address]Windows Firewall and Symantec protection are disabled.The client can browse the internet and ping the serverWhen browsing the network, the client can only see itself.Computer browser, DHCP, DNS, Network Connections, Network Location, RPC, Server, TCP/IP NEtbios Helper, Workstation services are all running.The local security policy has "Microsoft network client: Digitally sign communications" disabled.Net Use has no entries.I tried creating a new user account; same problem. Some entries from the event log that stood out: The following boot-start or system-start driver(s) failed to load: Aspi32, SymIMWMI: Event filter with query "SELECT * FROM __InstanceModificationEvent WITHIN 60 WHERE TargetInstance ISA "Win32_Processor" AND TargetInstance.LoadPercentage > 99" could not be reactivated in namespace "//./root/CIMV2" because of error 0x80041003. Events cannot be delivered through this filter until the problem is corrected. From the server's SMB log, I get a whole lot of those: [2012/02/03 13:54:06, 2, pid=70008] /SourceCache/samba/samba-235.6/samba/source/smbd/reply.c:reply_special(332) netbios connect: name1=192.168.1.222 name2=BLINKY [2012/02/03 13:54:06, 2, pid=70008] /SourceCache/samba/samba-235.6/samba/source/smbd/reply.c:reply_special(339) netbios connect: local=192.168.1.222 remote=blinky, name type = 0 [2012/02/03 13:54:06, 2, pid=70008] /SourceCache/samba/samba-235.6/samba/source/lib/module.c:do_smb_load_module(64) Module '/usr/lib/samba/auth/odsam.dylib' loaded [2012/02/03 13:54:06, 2, pid=70008] /SourceCache/samba/samba-235.6/samba/source/auth/auth.c:check_ntlm_password(319) check_ntlm_password: Authentication for user [] -> [] FAILED with error NT_STATUS_NO_SUCH_USER However I haven't found any entry with the Vista machine's name so this might be a red herring. I hope I've done due diligence to go through most of the common troubleshooting steps. What do you suggest?