prelude-notify: 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/prelude-notify - from package: prelude-notify

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

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