winswitch_away: command not found

Have You tried accessing the binary with the full path?

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_away - from package: winswitch

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