#install debian based:

sudo apt-get install nbtscan

#windows and others: download at http://www.unixwiz.net/tools/nbtscan.html

nbtscan 192.168.0.1-254 //IP Range
nbtscan 192.168.0.0/24  //whole C-class network
nbtscan 192.168.1.0/24  //whole C-class network
nbtscan 172.16.0.0/16   //Whole B-class network
nbtscan 10.0.0.0/8      //whole A-class network