You have a Broadcom chip.
Ubuntu has the drivers for it in their repos. You don't need ndiswrapper.
In the Synaptic Package Manager, go to Settings-->Repositories. On the Ubuntu tab, enable the "Restricted Drivers for Devices" repository. The Broadcom stuff is in there.
Also, somewhere in the Ubuntu menus, you can find something about "Additional Drivers," but I forget the exact wording and exactly where. That would likely lead you to the same place.
I have two Dells with that family of chips. They both worked under Ubuntu once I had the correct firmware from the repos.