I disabled NetBIOS over TCP on my XP test machine and can no longer browse CIFS shares on my Filer. LOoking at a network trace fomr a working machine it appears that the FIler wants to use CIFS over port 139 as opposed to port 445. Ms CIFS initially tries port 139 but preferes 445. When you disabled NetBIOS over TCP cleint side, it stops attempting to use port 139 and hence breaks comms with my filer. Anyway to get the filer to use 445?