kconf_update: 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 CentOS possible default full paths are:

/usr/bin/kconf_update - from package: kdelibs3

You may install the required package with command yum install {package}

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