winswitch_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 Debian possible default full paths are:

/usr/bin/winswitch_applet - from package: winswitch

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

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