kcmshell: 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/kcmshell - from package: kdelibs3

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

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