kdeinit4: 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/kdeinit4 - from package: kdelibs

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

On Debian possible default full paths are:

/usr/bin/kdeinit4 - from package: kdelibs-bin

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

Error in other languages:
kdeinit4: bevel nie gevind nie
kdeinit4: comandă negăsită
kdeinit4: comando não encontrado
kdeinit4: commande introuvable
kdeinit4: command not found
kdeinit4: käsku ei ole
kdeinit4: không tìm thấy lệnh
kdeinit4: komanda nerasta
kdeinit4: Kommando nicht gefunden.
kdeinit4: kommandot finns inte
kdeinit4: komut yok
kdeinit4: nie znaleziono polecenia
kdeinit4: níor aimsíodh an t-ordú
kdeinit4: no se encontró la orden
kdeinit4: no s'ha trobat l'ordre
kdeinit4: opdracht niet gevonden
kdeinit4: parancs nem található
kdeinit4: perintah tidak ditemukan
kdeinit4: príkaz nenájdený
kdeinit4: příkaz nenalezen
kdeinit4: команда не найдена
kdeinit4: командата не е открита
kdeinit4: 命令找不到
kdeinit4: コマンドが見つかりません