Firewall installation in XP closes cable modem connection

I've installed three different firewalls with the same result: each time I
lose access to the cable modem. The cable company can see the modem, but not
the computer. After each incident, I have restored the computer to a point
before the installation and connection to the modem (and the internet) has
been restored. I am now running the Windows firewall, but I would like a
more robust interface. What might be the source(s) of this problem?

Hi
Having a computer sitting directly on the Modem is Not a good idea.
My suggestion as a first step is to get a Cable/DSL Router.
Adding a Cable/DSL Router (even for a single computer) is a very good step
to provide further isolation from the Internet and maintaining your computer
as a private Network Device.
See more here, http://www.ezlan.net/firewall.html
Cable/DSL Routers (actually almost all of them are Wireless Cable/DSL
Routers) are very inexpensive (prices start around $20 on sales) and are
available in every store that sells computer related hardware.
Jack (MVP-Networking).

"cdanl05" <cdanl05@discussions.microsoft.com> wrote in message
news:F90B85EB-AD82-423F-A448-C69710447CA1@microsoft.com...
> I've installed three different firewalls with the same result: each time
> I
> lose access to the cable modem. The cable company can see the modem, but
> not
> the computer. After each incident, I have restored the computer to a
> point
> before the installation and connection to the modem (and the internet) has
> been restored. I am now running the Windows firewall, but I would like a
> more robust interface. What might be the source(s) of this problem?

Thank you for your reply; I followed the links, am now much better informed
about a router's contribution to online security, and have done some initial
(online) shopping. Sadly, your reply, while enormously informative, does not
address my problem of installing a firewall in XP without losing my modem
connection.

"Jack (MVP-Networking)." wrote:

> Hi
> Having a computer sitting directly on the Modem is Not a good idea.
> My suggestion as a first step is to get a Cable/DSL Router.
> Adding a Cable/DSL Router (even for a single computer) is a very good step
> to provide further isolation from the Internet and maintaining your computer
> as a private Network Device.
> See more here, http://www.ezlan.net/firewall.html
> Cable/DSL Routers (actually almost all of them are Wireless Cable/DSL
> Routers) are very inexpensive (prices start around $20 on sales) and are
> available in every store that sells computer related hardware.
> Jack (MVP-Networking).
>
> "cdanl05" <cdanl05@discussions.microsoft.com> wrote in message
> news:F90B85EB-AD82-423F-A448-C69710447CA1@microsoft.com...
> > I've installed three different firewalls with the same result: each time
> > I
> > lose access to the cable modem. The cable company can see the modem, but
> > not
> > the computer. After each incident, I have restored the computer to a
> > point
> > before the installation and connection to the modem (and the internet) has
> > been restored. I am now running the Windows firewall, but I would like a
> > more robust interface. What might be the source(s) of this problem?
>
>