update-rcconf-guide: 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/sbin/update-rcconf-guide - from package: rcconf

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

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