Downloaded the latest vers of ndiswrapper. It's a .tar.gz. I don't know what to do to install this file. I do something like

and it says it can't find the file. I am in the right directory on the terminal /home/usern

A tar.gz is not a package manager package but rather a gzipped tar bundle.

tar is a utility used to make "archives" (backups) that is commonly used for bundling files for easy transport.

gzip is a utility for compressing files. Compressing tar bundles reduces bandwidth when they are transferred over networks.

You can run:
tar tzvf ndiswrapper-1.42.tar.gz

To see what is in the bundle - the "t" tells it to just list and the "z" tells it to gunzip.

You can extract what you see in with "t" by changing it to "x":
tar xzvf ndiswrapper-1.42.tar.gz

However, rather than running the above you might want to use apt-get for ndiswrapper (without the suffix) to see if any of the repositories you have defined a prepackaged bundle for your distro.

Typically the .tar.gz distributions are so you can config and compile your own. Look for a "README" file in the tar.gz bundle if you choose to go that way.

Thank you very much for that thorough explanation. I am obviously new to the world of Linux and am bombarded with new terminology and processes.