xpbs: 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/xpbs - from package: torque-gui

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

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