ndiswrapper-1.9: 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
/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/sbin/ndiswrapper-1.9 - from package: ndiswrapper-utils-1.9

You may install the required package with command apt-get install {package}
Error in other languages:
ndiswrapper-1.9: bevel nie gevind nie
ndiswrapper-1.9: comandă negăsită
ndiswrapper-1.9: comando não encontrado
ndiswrapper-1.9: commande introuvable
ndiswrapper-1.9: command not found
ndiswrapper-1.9: käsku ei ole
ndiswrapper-1.9: không tìm thấy lệnh
ndiswrapper-1.9: komanda nerasta
ndiswrapper-1.9: Kommando nicht gefunden.
ndiswrapper-1.9: kommandot finns inte
ndiswrapper-1.9: komut yok
ndiswrapper-1.9: nie znaleziono polecenia
ndiswrapper-1.9: níor aimsíodh an t-ordú
ndiswrapper-1.9: no se encontró la orden
ndiswrapper-1.9: no s'ha trobat l'ordre
ndiswrapper-1.9: opdracht niet gevonden
ndiswrapper-1.9: parancs nem található
ndiswrapper-1.9: perintah tidak ditemukan
ndiswrapper-1.9: príkaz nenájdený
ndiswrapper-1.9: příkaz nenalezen
ndiswrapper-1.9: команда не найдена
ndiswrapper-1.9: командата не е открита
ndiswrapper-1.9: 命令找不到
ndiswrapper-1.9: コマンドが見つかりません