My experience with software firewalls is that they chew performance. I recommend software firewalls for dial up users.....but as JP stated if you are on cable or dsl ...spend the 100 bucks.
I have heard too many horror stories of fresh installs getting infected...trying to get the updates from ms and av companies


As for 2 anti virus...that will cause problems....

I use an online scanner as a backup to the AV I have installed on the ws...if a machine is infected with a virus...I clean using it a local av ( as some viruses are easy to clean in safe mode)...then I use an online scanner to be sure I got it all.

just disable the local av til the online scan is done.

mlf