nuapplet2: 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/nuapplet2 - from package: nuapplet

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

Error in other languages:
nuapplet2: bevel nie gevind nie
nuapplet2: comandă negăsită
nuapplet2: comando não encontrado
nuapplet2: commande introuvable
nuapplet2: command not found
nuapplet2: käsku ei ole
nuapplet2: không tìm thấy lệnh
nuapplet2: komanda nerasta
nuapplet2: Kommando nicht gefunden.
nuapplet2: kommandot finns inte
nuapplet2: komut yok
nuapplet2: nie znaleziono polecenia
nuapplet2: níor aimsíodh an t-ordú
nuapplet2: no se encontró la orden
nuapplet2: no s'ha trobat l'ordre
nuapplet2: opdracht niet gevonden
nuapplet2: parancs nem található
nuapplet2: perintah tidak ditemukan
nuapplet2: príkaz nenájdený
nuapplet2: příkaz nenalezen
nuapplet2: команда не найдена
nuapplet2: командата не е открита
nuapplet2: 命令找不到
nuapplet2: コマンドが見つかりません