wdreg: 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/wdreg - from package: freewnn-jserver

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

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