hachoir-metadata-gtk: 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

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/hachoir-metadata-gtk - from package: python-hachoir-metadata

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