krenew: 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/krenew - from package: kstart

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

On Debian possible default full paths are:

/usr/bin/krenew - from package: kstart

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

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