It is not necessary to run the software that is Windows based to set up a
network.. Chances are that Verizon and many ISPs are running their networks on
Linux. Many servers use LAMP (Linux, Apache, MySQL and PHP). It is the heart of
the internet. So it is possible to set up a server that runs Linux and connects
to the outside through your modem and to your network through it. It is not
necessary to run Windows at all provided (and it is a big one) we can get your
computer to detect and install the modem.

I have had both DSL and cable modems and have never had to run any Windows
software. I set up my modem and my network through my web browser. As far as
either was concerned it did not matter what OS I was running. All I needed was
to point the browser to my router or modem and then the hardware recognized it.

Two things to note from all of this. Running networks is what Linux is made to
do and modems and routers are made to work with browsers. Neither cares about
the OS particularly. It is just the delivery mechanism.

A server run on Linux will be more secure, won't crash and will never need to be
re-booted. Since Linux is modular you can add servers as ou want at anytime. You
can even get special distros made for the purpose such as Untangle. I tried it
out as a VM appliance, but have not run it specifically for its intended
purpose, but it gets great reviews.
www.howtoforge.com/...ering-with-the-untangle-5.3-\
network-gateway (for one such review)