PolyGUI2: 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/PolyGUI2 - from package: polybori-gui

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

Error in other languages:
PolyGUI2: bevel nie gevind nie
PolyGUI2: comandă negăsită
PolyGUI2: comando não encontrado
PolyGUI2: commande introuvable
PolyGUI2: command not found
PolyGUI2: käsku ei ole
PolyGUI2: không tìm thấy lệnh
PolyGUI2: komanda nerasta
PolyGUI2: Kommando nicht gefunden.
PolyGUI2: kommandot finns inte
PolyGUI2: komut yok
PolyGUI2: nie znaleziono polecenia
PolyGUI2: níor aimsíodh an t-ordú
PolyGUI2: no se encontró la orden
PolyGUI2: no s'ha trobat l'ordre
PolyGUI2: opdracht niet gevonden
PolyGUI2: parancs nem található
PolyGUI2: perintah tidak ditemukan
PolyGUI2: príkaz nenájdený
PolyGUI2: příkaz nenalezen
PolyGUI2: команда не найдена
PolyGUI2: командата не е открита
PolyGUI2: 命令找不到
PolyGUI2: コマンドが見つかりません