qenable: 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/qenable - from package: torque-client

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

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