gkdebconf: 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/gkdebconf - from package: gkdebconf

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

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