kwboot: 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/kwboot - from package: u-boot-tools

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

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