Cannot view other computers in my network

I originally, I had Vista and I have genuine Windows 7 RC. When we set up Windows7, we couldn't find out how to connect to our other computers.

I'm trying to play a game over my network with other computers, but I can't see them because of my problem. I can't use HomeGroup because these are XP computers. What should I try? I'm not very intelligent with this the networks, so please say it so I can understand it, haha. I'm 13.

And just say if you need more info. I don't really know what I can give.

Poiuy

try a ipconfig /all in cmd and let us know the results.
also let us know if any firewall is installed and whether it is blocking the access.
are you able to ping the other computer?
let us know the details, we wil try to help.

glad a 13 yr trying RC. Kudos bro.