k3guitune: 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/k3guitune - from package: k3guitune

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

Error in other languages:
k3guitune: bevel nie gevind nie
k3guitune: comandă negăsită
k3guitune: comando não encontrado
k3guitune: commande introuvable
k3guitune: command not found
k3guitune: käsku ei ole
k3guitune: không tìm thấy lệnh
k3guitune: komanda nerasta
k3guitune: Kommando nicht gefunden.
k3guitune: kommandot finns inte
k3guitune: komut yok
k3guitune: nie znaleziono polecenia
k3guitune: níor aimsíodh an t-ordú
k3guitune: no se encontró la orden
k3guitune: no s'ha trobat l'ordre
k3guitune: opdracht niet gevonden
k3guitune: parancs nem található
k3guitune: perintah tidak ditemukan
k3guitune: príkaz nenájdený
k3guitune: příkaz nenalezen
k3guitune: команда не найдена
k3guitune: командата не е открита
k3guitune: 命令找不到
k3guitune: コマンドが見つかりません