iso: 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/iso - from package: fonty-rg

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

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