how-can-i-help: 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 Debian possible default full paths are:

/usr/bin/how-can-i-help - from package: how-can-i-help

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

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