ntfsundelete: 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:

/sbin/ntfsundelete - from package: ntfsprogs
/usr/sbin/ntfsundelete - from package: ntfsprogs

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

On Debian possible default full paths are:

/sbin/ntfsundelete - from package: ntfs-3g

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

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