xkbcomp: 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/xkbcomp - from package: xorg-x11-xkb-utils

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

On Debian possible default full paths are:

/usr/bin/xkbcomp - from package: x11-xkb-utils

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

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