kdepasswd: command not found

Have You tried accessing the binary with the full path?

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/kdepasswd - from package: kdebase

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

On Debian possible default full paths are:

/usr/bin/kdepasswd - from package: kdepasswd

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