network 2

hi i have adsl and 2 computers on a network running through a swich they both have the net but the file sharing wont work and we cant play lan games what should i do my ips are auto on both computer or my net dont work one computer has xp pro and the other home ive set the file sharing but (can u tell me how so i know if i did it right)the workgroups are the sameand my swich has the net on port 1 (cause it has know set port on the back for one)and the other computers are using 1 and 2 and the fire walls are on but we cant ping each other plz help