pmkpc: 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/pmkpc - from package: pmk

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

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