wbemec: command not found

Have You tried accessing the binary with the full path?

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/wbemec - from package: sblim-wbemcli

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