immstool: 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/immstool - from package: imms-common

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

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