kcmshell4: 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/kcmshell4 - from package: kdebase-runtime

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

On Debian possible default full paths are:

/usr/bin/kcmshell4 - from package: kde-runtime

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

Error in other languages:
kcmshell4: bevel nie gevind nie
kcmshell4: comandă negăsită
kcmshell4: comando não encontrado
kcmshell4: commande introuvable
kcmshell4: command not found
kcmshell4: käsku ei ole
kcmshell4: không tìm thấy lệnh
kcmshell4: komanda nerasta
kcmshell4: Kommando nicht gefunden.
kcmshell4: kommandot finns inte
kcmshell4: komut yok
kcmshell4: nie znaleziono polecenia
kcmshell4: níor aimsíodh an t-ordú
kcmshell4: no se encontró la orden
kcmshell4: no s'ha trobat l'ordre
kcmshell4: opdracht niet gevonden
kcmshell4: parancs nem található
kcmshell4: perintah tidak ditemukan
kcmshell4: príkaz nenájdený
kcmshell4: příkaz nenalezen
kcmshell4: команда не найдена
kcmshell4: командата не е открита
kcmshell4: 命令找不到
kcmshell4: コマンドが見つかりません