Are you using Virgin's ADSL service or Cable?
If cable, you shouldn't need to use a "Setup" disk. Power off the Cable Modem for three or four minutes (that is IMPORTANT) so that it loses the association between the existing connection and the IP address it has allocated to it. Connect the ethernet cable between the Cable Modem and PC. Power on the Modem and, once it is fully booted with all lights on, boot the PC, which should get its IP and other addresses and you should be online.