To install the ndiswrapper you do need an Internet connection. However since the wget command worked I assume you have alternative Internet access on the machine. This being the case you can install ndiswrapper from the desktop using synaptic package manager or from the command line using apt-get or aptitude.
To install via aptitude use the command.
Code:
sudo aptitude install ndiswrapper-common ndiswrapper-module-1.9 ndiswrapper-utils-1.9
You may need to activate the universe and/or multiverse repositorys. you can do this by editing etc/apt/sources.list or by using the software sources program in System>Administration. I would suggest the latter as it will keep the source.list file well commented.