Well first of all, have you tried to ping the XP machine? If you can, then it's not a hardware problem. If it says destination host unreachable, then you probably have your XP machine set to DHCP, and so it assigned itself a class B i.p. address of 169.254.xxx.xxx. This means you need to change your i.p. to something that is in the same subnet as your other three. I hope you are using TCP/IP. The workgroup really shouldn't matter with XP. Also, to access files on an NT, 2000, or XP machine, you must have a user account on that machine that is the same as the one you are trying to access it from. When you say you used the floppy setup on the other ones, are you talking about not being able to use Internet Connection Sharing?