xset: 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 CentOS possible default full paths are:

/usr/bin/xset - from package: xorg-x11-server-utils

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

On Debian possible default full paths are:

/usr/bin/xset - from package: x11-xserver-utils

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