nbtscan: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/nbtscan - from package: nbtscan

You may install the required package with command apt-get install {package}

Error in other languages:
nbtscan: bevel nie gevind nie
nbtscan: comandă negăsită
nbtscan: comando não encontrado
nbtscan: commande introuvable
nbtscan: command not found
nbtscan: käsku ei ole
nbtscan: không tìm thấy lệnh
nbtscan: komanda nerasta
nbtscan: Kommando nicht gefunden.
nbtscan: kommandot finns inte
nbtscan: komut yok
nbtscan: nie znaleziono polecenia
nbtscan: níor aimsíodh an t-ordú
nbtscan: no se encontró la orden
nbtscan: no s'ha trobat l'ordre
nbtscan: opdracht niet gevonden
nbtscan: parancs nem található
nbtscan: perintah tidak ditemukan
nbtscan: príkaz nenájdený
nbtscan: příkaz nenalezen
nbtscan: команда не найдена
nbtscan: командата не е открита
nbtscan: 命令找不到
nbtscan: コマンドが見つかりません