rcconf: 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/rcconf - from package: rcconf

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

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