Yes, it is. I don't have WiFi and it's installed anyway. You can install it with (and see if a reinstall helps)
sudo apt-get install --reinstall ndiswrapper-common ndiswrapper-dkms ndisgtk ndiswrapper-utils-1.9
My Linux history: Ubuntu 10.04 - 10.10 - LMDE 201109 - UP4 My sources.list/preferences
Computers is not science. And it's not magic - it's something in between.