freqtweak: 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/freqtweak - from package: freqtweak

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

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