ppufiles-2.6.4: 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/ppufiles-2.6.4 - from package: fp-utils-2.6.4

You may install the required package with command apt-get install {package}
Error in other languages:
ppufiles-2.6.4: bevel nie gevind nie
ppufiles-2.6.4: comandă negăsită
ppufiles-2.6.4: comando não encontrado
ppufiles-2.6.4: commande introuvable
ppufiles-2.6.4: command not found
ppufiles-2.6.4: käsku ei ole
ppufiles-2.6.4: không tìm thấy lệnh
ppufiles-2.6.4: komanda nerasta
ppufiles-2.6.4: Kommando nicht gefunden.
ppufiles-2.6.4: kommandot finns inte
ppufiles-2.6.4: komut yok
ppufiles-2.6.4: nie znaleziono polecenia
ppufiles-2.6.4: níor aimsíodh an t-ordú
ppufiles-2.6.4: no se encontró la orden
ppufiles-2.6.4: no s'ha trobat l'ordre
ppufiles-2.6.4: opdracht niet gevonden
ppufiles-2.6.4: parancs nem található
ppufiles-2.6.4: perintah tidak ditemukan
ppufiles-2.6.4: príkaz nenájdený
ppufiles-2.6.4: příkaz nenalezen
ppufiles-2.6.4: команда не найдена
ppufiles-2.6.4: командата не е открита
ppufiles-2.6.4: 命令找不到
ppufiles-2.6.4: コマンドが見つかりません