xgfconfig: 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/xgfconfig - from package: xgridfit

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