Windows XP and Windows Vista networking issues

yes you have it but maybe it's disabled; FIXIT immediately.

let's go thru some basics;
the router gives you NAT and SPI which allows you to share the ISP connection
and to filter bad packets(spi).

it has port forwarding feature, but most of the time you want that OFF.

every system that connects to the Internet needs a firewall.
Its job is to stop inbound data that was not requested (can't be relevant and therefore is untrustworthy).

This creates conditions where your LAN systems would be unable to share files and printer,
so we need to tell the firewall to ALLOW traffic from known locations on know ports.

does this help?

Yes it makes sense. But I want to keep the firewalls off because they cause annoying problems. If I do that I don't need to allow traffic from known locations because its going to be allowing everything

File/printer sharing isn't a problem at all! Its working great. I just need to configure things to get LAN games working correctly, and full download speeds on bittorrent (2.2mbps rather than a maximum of 500kbps)

The failsafe to getting LAN games working correct could well be installing Vista on the XP machine, but with AMD 3500+/1gb RAM/6800GT 256mb Vista is a little sloppy on it. I am sure there is a way to configure the computers/router to get LAN games working. I have actually done it successfully before by removing internet and the router completely and creating a network without an internet connection. This tells me that when its all configured to use the internet/router something that allows connection for LAN games is turned off

well it's your choice. imo quite foolish. you have no means to either protect from nor even determine if you're being attacked. good luck.