Setting up a Secure Network...

I have spent several hours trying to research this on this internet, but with my lack of networking knowledge, I am not even really sure what I am searching for anymore.

Help would be much appreciated.

I would like to setup a separate network between 2 computers that would be password protected or another network that no other computer can see other than the specified 2. Here are specs:

-both pc's have winxp pro
-all users are connected to a lan which is hosted on a separate server
-all users also sign in locally, not within the network(this is obviously the main problem)

not sure if the helper would need anymore info. of course once again due to my lack of networking knowledge

If these stations don't need any of the resources available on the lan then simply give each machine a different ip range then the lan. So lets say your lan is 192.168.0.x you could assign 192.168.100.2 and 192.168.100.3 to pc1 and pc2. This would allow them to communication with each other but not with anyone else on the network.

you could create a second vlan for the two computers in your switch with no routing inbetween, or setup routing between them with ACLs or use a firewall to connect them using authentication proxy or just use ACLs with the firewall.