You can use any ISP but you will be supplied with an external modem Modem this needs to connect to the router or pc via ethernet (rj45) not USB. You simply put an ethernet (10/100 network card)card in each pc then connect these to the router and attach the router to the modem. Run the disk with the router If you want to share files across the pc's run XP networking wizard (turn off firewalls first)then with a bit of luck its all up and running. Once you know the ISP and the modem we can help with the hardware. click here and have a look.