A computer, with Windows 7, can't access any website by domain suddenly. Whether this computer use a wired link or connect to the WLAN, The fault persists IP and DNS obtained automatically, and seems normal (ipconfig /all return the correct info) I can visit websites by using HTTP proxy The DNS server is available, other computer in my room works properly. I can ping myself, the gateway and any other IP, but domains I can use nslookup and obtain the correct IP info There are some error information in the event log about dns client events explaining the client can not verify the DNS server available Windows network diagnosis explain that Windows can't communicate with the device or resource (Primary DNS Server) I guess the dns client should be blame. I tried to do the following things but the fault persist. Reinstall the driver of network adapter Reset TCP/IP (netsh int ip reset) Reset Winsock (netsh winsock reset) Reset LSP I don't want to reinstall the whole os, what should I do?