I've got a problem. Ive got a computer that won't resolve dns names to IP addresses. The customer claims that no new software was installed right before it happenned (Yeah, ok); anyway. I have tried everything that I can think of. I can ping IP addresses anywhere on the net. When I try to ping a url in dos I get unknown host name, so I know its not an IE problem. I have checked for viruses, and ran Spybot. I can ping thier DNS server which is set dynamically. I tried using another know working dns server set statically with no luck. I have also gone through the add/remove programs and removed all of what I feel is the junk software in there. Popup stoppers, web enhancers, search bars, ect. I am stumped. Any suggestions?

start -> run -> sfc scan for altered files and replace the ones that come up, then extract one from disk, extract winsock.dll and wsock32.dll from the windows cd, reboot computer if the winsocks are bad in windows, it won't resolve dns addresses

Thank you for the suggestion. I tried what you said and that didn't fix the problem. It reported as replacing 5 files. Then I replaced the 2 winsock files. Restarted and still the same problem.