gzrecover: 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 Debian possible default full paths are:

/usr/bin/gzrecover - from package: gzrt

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

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