We have a small domain based network dominated by Windows XP PCs. Starting about a week ago, two of our Windows 7 PCs began having a problem where they can not access the internet, but have nice speedy access to our Windows Server 2008 based network shares. Now the other two Windows 7 PCs are affected. Making the problem even more bizarre, two of the computers have worked correctly for at least one day during this period, seemingly randomly, and both during different time periods. Pinging the gateway from these PCs results in some "Destination host unreachable" responses and some requests timing out. These PCs are able to obtain IP addresses normally. Based on this thread and other Googling, I have tried the following unsuccessfully: Manually configured an IP address, etc. Disabled and re-enabled network adapters Disabled all IPV6 in the network card. Rebuilt the IP stack. Turned off IP Helper Service Turned off HomeGroup Services Turned off Symantec Endpoint Security Any ideas would be appreciated!