install.mpb: 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"

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