Notes:
$ nbtscan 192.168.1.0/24
Doing NBT name scan for addresses from 192.168.1.0/24
IP address NetBIOS Name Server User MAC address
------------------------------------------------------------------------------
192.168.1.7 SAM <server> UNCLE SAM 00-50-ba-8a-19-0f
192.168.1.5 DATABASE <server> ORACLE MAN 00-00-00-00-00-00
192.168.1.50 KERRY <server> KERRY LIVGREN 00-50-da-b4-30-5d
192.168.1.53 MONTY <server> MONTY COLVIN 32-db-2a-0b-af-75
...
A MAC address of 00-00-00-00-00-00 usually indicates the platform is NOT a Windows platform. The host is probably running Samba (http://www.samba.org) or other SMB protocol clone.