When I first set up the dsl modem, it did give my computer a private ip address.  I looked through the paperwork that came with it and figured out how to make it give me a public ip address.

Thanks for the suggestions.

Derek
On 8/7/2012 22:43, JD Austin wrote:
If you're already behind a router (often dsl modem) you might be 'double natting' if you don't configure it right.  
I never like to mix uses but it can work though.  My recommendation would be to take an older piece of hardware and install SME Server (if you want a directory server/file server  for windows),or one of these firewall distributions if you dont: smoothwall, endian firewall, or ip-cop.
On SME Server the windows machines need a registry patch (especially Vista+) http://<localgateway IP>/server-resources/regedit/