loadndisdriver: 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:

/sbin/loadndisdriver - from package: ndiswrapper-common

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

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