btlaunchmany.bittorrent: 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/btlaunchmany.bittorrent - from package: bittorrent

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