certwatch: 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/certwatch - from package: crypto-utils

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

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