bluetooth-applet: 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 CentOS possible default full paths are:

/usr/bin/bluetooth-applet - from package: gnome-bluetooth

You may install the required package with command yum install {package}

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