hpipower: 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/hpipower - from package: openhpi32
/usr/bin/hpipower - from package: openhpi

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

On Debian possible default full paths are:

/usr/bin/hpipower - from package: openhpi-clients

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

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