Alot of isp's have a range of ips the issue they dont always match the area that they are listed to that's the registered location. Isp's use dhcp servers like home routers do, just on large scale. The error you are getting is because two computers on your network have the same ip set. And easy way to fix that is insure dhcp is enabled on all of your machines and then run ipconfig /release and the ipconfig /renew from the cmd line. to get to that type cmd in the run menu.
I hope that helps some