PolyGUI: 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/PolyGUI - from package: polybori-gui

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

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