Turn pc in to firewall?

I have 1 spare pc and 1 spare laptop with alot of memory and hd space.what would i need to turn them in to a firewall.i have a wifi router which is netgear i also have aol as my isp.i want my pc to act as a firewall to protect all my connections too and from the wifi router.what would i need to do this?i only have one network adaptor would i need two in the back of my pc/laptop or would i have to but some network hubs.i do not want to splash out on hardware firewall and i not want to splash out on software and i do not trust free firewalls so i would like to put my spare computer to use as a firewall.any help and advice on what hardware i would need in my pc or laptop woulc be cool.if you use a windows built in firewall then more fool you.even i can get past windows firewall.you might as well as ya grandma to gaurd your pc.
Answer
Sorry for coming across as a bit cheeky but if your so good that you can get round windows firewall, you should know where to look for setting up your old pc as a hardware firewall.besides this your router also should have one built inone avenue you should explore is using a linux based operating system configured as a firewall. there are many releases out there depending on how secure you want it and how easy you want to maintain it. i just cant see how someone so bright who can get through windows firewall would need someones help on yahoo answers about hardware firewalls.if your thinking about updating your post i would love to know how you get round the windows firewall so easily...