Happened on my friends 2k box as well. our companies web mail worked from her PC. Her schools web mail didn't and hotmail didn't. Shes on a cable modem from an ISP. ipconfig /renew sometimes returns error that DHCP server could not be reached. Then I restart and I get a lease. Once the lease indicated 192.168.1.1 gateway and 192.168.1.2 her IP address??? She has no router or NAT. She is connecting directly to the ISPs network.