crossover network 2

my modem is using usb but the problem is i cant access the shared files on the network the weird thing is i had it going and i got a virus and it stuffed up so i removed the viurs and it didnt work so i formated and i was working for a bit but now i stoped again so wat im asking is how do i setup my network so i can play lan games and access the other computer’s files what should i put in as my ips and stuff again cause i tryed what u all said and it didnt work i should be able to set up the internet sharing after i get the network going thanks