ifpgui: 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/ifpgui - from package: ifpgui

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

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