setscheduler: 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/setscheduler - from package: kdebase-workspace

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

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