nvdecompress: 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/nvdecompress - from package: libnvtt-bin

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

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