chkconf: 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/chkconf - from package: ircd-irc2

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

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